Add extern for 'led' global, set 'weak' attribute for rgblight_set()

quantum/rgblight.h

@@ -40,6 +40,8 @@
 #include "eeconfig.h"
 #include "light_ws2812.h"
 
+extern LED_TYPE led[RGBLED_NUM];
+
 extern const uint8_t RGBLED_BREATHING_INTERVALS[4] PROGMEM;
 extern const uint8_t RGBLED_RAINBOW_MOOD_INTERVALS[3] PROGMEM;
 extern const uint8_t RGBLED_RAINBOW_SWIRL_INTERVALS[3] PROGMEM;