Create keycodes for RGB control functions

Moves RGB controls out of the macro function and assigns them their own
keycodes:
RGB_TOG (toggle on/off)
RGB_MOD (mode step)
RGB_HUI (increase hue)
RGB_HUD (decrease hue)
RGB_SAI (increase saturation)
RGB_SAD (decrease saturation)
RGB_VAI (increase brightness)
RGB_VAD (decrease brightness)

quantum/keymap.h

@@ -156,6 +156,16 @@ enum quantum_keycodes {
     BL_INC,
     BL_TOGG,
     BL_STEP,
+	
+	// RGB functionality
+	RGB_TOG,
+	RGB_MOD,
+	RGB_HUI,
+	RGB_HUD,
+	RGB_SAI,
+	RGB_SAD,
+	RGB_VAI,
+	RGB_VAD,
 
     // Left shift, open paren
     KC_LSPO,