[Keyboard] Helix use `post_rules.mk` (#14216)

* Helix/pico use post_rules.mk insted of local_features.mk

Tested with the following procedure.
```
git checkout 77a93fec79 (qmk/develop)
make clean
make helix/pico:all:check-md5
make helix/pico/sc:all:check-md5
git checkout helix_use_post_rules.mk
make clean
make helix/pico:all:check-md5
make helix/pico/sc:all:check-md5
```

* Helix/rev2 use post_rules.mk

Tested with the following procedure.
```
git checkout 77a93fec79 (qmk/develop)
make clean
make helix/pico:all:check-md5
make helix/pico/sc:all:check-md5
make helix/rev2:all:check-md5
make helix/rev2/sc:all:check-md5
git checkout helix_use_post_rules.mk
make clean
make helix/pico:all:check-md5
make helix/pico/sc:all:check-md5
make helix/rev2:all:check-md5
make helix/rev2/sc:all:check-md5
```

1 files changed, 0 insertions, 149 deletions

diff --git a/keyboards/helix/pico/local_features.mk b/keyboards/helix/pico/local_features.mk
deleted file mode 100644
index be5c739f97..0000000000
--- a/keyboards/helix/pico/local_features.mk
+++ /dev/null
@@ -1,149 +0,0 @@
-#
-#  local_features.mk contains post-processing rules for the Helix keyboard.
-#
-#   Post-processing rules convert keyboard-specific shortcuts (that represent
-#   combinations of standard options) into QMK standard options.
-#
-
-KEYBOARD_LOCAL_FEATURES_MK :=
-
-define HELIX_CUSTOMISE_MSG
-  $(info Helix Spacific Build Options)
-  $(info -  OLED_ENABLE          = $(OLED_ENABLE))
-  $(info -  LED_BACK_ENABLE      = $(LED_BACK_ENABLE))
-  $(info -  LED_UNDERGLOW_ENABLE = $(LED_UNDERGLOW_ENABLE))
-  $(info -  LED_ANIMATIONS       = $(LED_ANIMATIONS))
-  $(info -  IOS_DEVICE_ENABLE    = $(IOS_DEVICE_ENABLE))
-  $(info )
-endef
-
-define HELIX_HELP_MSG
-  $(info Helix keyboard convenient command line option)
-  $(info -    make HELIX=<options> helix/pico:<keymap>)
-  $(info -    option= oled | back | under | na | no-ani)
-  $(info -             ios | sc | split-common | scan | verbose)
-  $(info -    ex.)
-  $(info -      make HELIX=oled     helix/pico:<keymap>)
-  $(info -      make HELIX=back     helix/pico:<keymap>)
-  $(info -      make HELIX=under    helix/pico:<keymap>)
-  $(info -      make HELIX=back,na  helix/pico:<keymap>)
-  $(info -      make HELIX=back,ios helix/pico:<keymap>)
-  $(info )
-endef
-
-  ifneq ($(strip $(HELIX)),)
-    COMMA=,
-    helix_option := $(subst $(COMMA), , $(HELIX))
-    ifneq ($(filter help,$(helix_option)),)
-      $(eval $(call HELIX_HELP_MSG))
-      $(error )
-    endif
-    ifneq ($(filter oled,$(helix_option)),)
-      OLED_ENABLE = yes
-    endif
-    ifneq ($(filter back,$(helix_option)),)
-      LED_BACK_ENABLE = yes
-    else ifneq ($(filter under,$(helix_option)),)
-      LED_UNDERGLOW_ENABLE = yes
-    endif
-    ifneq ($(filter na,$(helix_option)),)
-      LED_ANIMATIONS = no
-    endif
-    ifneq ($(filter no_ani,$(helix_option)),)
-      LED_ANIMATIONS = no
-    endif
-    ifneq ($(filter no-ani,$(helix_option)),)
-      LED_ANIMATIONS = no
-    endif
-    ifneq ($(filter ios,$(helix_option)),)
-      IOS_DEVICE_ENABLE = yes
-    endif
-    ifneq ($(filter sc,$(helix_option)),)
-      SPLIT_KEYBOARD = yes
-    endif
-    ifneq ($(filter split-common,$(helix_option)),)
-      SPLIT_KEYBOARD = yes
-    endif
-    ifneq ($(filter scan,$(helix_option)),)
-      # use DEBUG_MATRIX_SCAN_RATE
-      # see docs/newbs_testing_debugging.md
-      OPT_DEFS +=  -DDEBUG_MATRIX_SCAN_RATE
-      CONSOLE_ENABLE = yes
-      SHOW_VERBOSE_INFO = yes
-    endif
-    ifneq ($(filter verbose,$(helix_option)),)
-      SHOW_VERBOSE_INFO = yes
-    endif
-    SHOW_HELIX_OPTIONS = yes
-  endif
-
-ifneq ($(strip $(SPLIT_KEYBOARD)), yes)
-  SRC += local_drivers/serial.c
-  KEYBOARD_PATHS += $(HELIX_TOP_DIR)/local_drivers
-
-  # A workaround until #7089 is merged.
-  #   serial.c must not be compiled with the -lto option.
-  #   The current LIB_SRC has a side effect with the -fno-lto option, so use it.
-  LIB_SRC += local_drivers/serial.c
-
-  CUSTOM_MATRIX = yes
-
-  SRC += pico/matrix.c
-  SRC += pico/split_util.c
-endif
-
-########
-# convert Helix-specific options (that represent combinations of standard options)
-#   into QMK standard options.
-
-ifeq ($(strip $(LED_BACK_ENABLE)), yes)
-  RGBLIGHT_ENABLE = yes
-  OPT_DEFS += -DRGBLED_BACK
-  ifeq ($(strip $(LED_UNDERGLOW_ENABLE)), yes)
-    $(eval $(call HELIX_CUSTOMISE_MSG))
-    $(error LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE both 'yes')
-  endif
-else ifeq ($(strip $(LED_UNDERGLOW_ENABLE)), yes)
-  RGBLIGHT_ENABLE = yes
-endif
-
-ifeq ($(strip $(IOS_DEVICE_ENABLE)), yes)
-    OPT_DEFS += -DIOS_DEVICE_ENABLE
-endif
-
-ifeq ($(strip $(LED_ANIMATIONS)), yes)
-    OPT_DEFS += -DLED_ANIMATIONS
-endif
-
-ifeq ($(strip $(OLED_ENABLE)), yes)
-    SRC += local_drivers/i2c.c
-    SRC += local_drivers/ssd1306.c
-    KEYBOARD_PATHS += $(HELIX_TOP_DIR)/local_drivers
-    OPT_DEFS += -DOLED_ENABLE
-    ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
-        OPT_DEFS += -DLOCAL_GLCDFONT
-    endif
-endif
-
-ifeq ($(strip $(AUDIO_ENABLE)),yes)
-  ifeq ($(strip $(RGBLIGHT_ENABLE)),yes)
-    LTO_ENABLE = yes
-  endif
-  ifeq ($(strip $(OLED_ENABLE)),yes)
-    LTO_ENABLE = yes
-  endif
-endif
-
-ifneq ($(strip $(SHOW_HELIX_OPTIONS)),)
-  $(eval $(call HELIX_CUSTOMISE_MSG))
-  ifneq ($(strip $(SHOW_VERBOSE_INFO)),)
-     $(info -- RGBLIGHT_ENABLE    = $(RGBLIGHT_ENABLE))
-     $(info -- CONSOLE_ENABLE     = $(CONSOLE_ENABLE))
-     $(info -- OPT_DEFS           = $(OPT_DEFS))
-     $(info -- SPLIT_KEYBOARD     = $(SPLIT_KEYBOARD))
-     $(info -- LTO_ENABLE         = $(LTO_ENABLE))
-     $(info )
-  endif
-endif
-
-OLED_ENABLE = no # disable OLED in TOP/common_features.mk