Add support for RGB LEDs wired directly to each half's controller (#5392)

* Add support for wiring RGB LEDs for both halves directly to their respective controllers

RGB LEDs for each half don't need to be chained together across the TRRS cable with this

* Add split RGB LED support for serial

* Update config/rules for bakingpy layout

* Un-nest ifdefs for hand detection

* Read RGB config state from memory instead of EEPROM for serial updates

* Reuse existing LED pointer instead of creating new one

quantum/rgblight.h

@@ -197,6 +197,7 @@ void rgblight_setrgb_master(uint8_t r, uint8_t g, uint8_t b);
 void rgblight_setrgb_slave(uint8_t r, uint8_t g, uint8_t b);
 void rgblight_sethsv_master(uint16_t hue, uint8_t sat, uint8_t val);
 void rgblight_sethsv_slave(uint16_t hue, uint8_t sat, uint8_t val);
+void rgblight_set_clipping_range(uint8_t start_pos, uint8_t num_leds);
 
 uint32_t eeconfig_read_rgblight(void);
 void eeconfig_update_rgblight(uint32_t val);