Change keyboard level include guards to pragma once (#14248)

* Change keyboard level include guards to `pragma once`

And clean up a lot of layout macros

* Oops

* Remove dangling endif

keyboards/planck/keymaps/aviator/config.h

@@ -1,9 +1,8 @@
-#ifndef CONFIG_USER_H
-#define CONFIG_USER_H
+#pragma once
 
 #include "config_common.h"
 
-#ifndef LIGHT_CONFIG_H
+#ifndef KEYBOARD_planck_light
 #define BACKLIGHT_BREATHING
 #define BREATHING_PERIOD 3
 #endif
@@ -40,5 +39,3 @@
 
 /* override number of MIDI tone keycodes (each octave adds 12 keycodes and allocates 12 bytes) */
 //#define MIDI_TONE_KEYCODE_OCTAVES 2
-
-#endif