Moving rgb typedefs into a single location (#5978)

Because someone named the define poorly

Using full relative path as handwired/promethium has a color.h file

keyboards/handwired/promethium/rgbsps.c

@@ -1,7 +1,7 @@
 #include "ws2812.h"
 #include "rgbsps.h"
 
-struct cRGB led[RGBSPS_NUM];
+cRGB led[RGBSPS_NUM];
 
 void rgbsps_set(uint8_t index, uint8_t r, uint8_t g, uint8_t b) {
   led[index].r = r;