Change include guards in tmk_core/ and drivers/ to pragma once (#11240)

tmk_core/common/suspend.h

@@ -1,5 +1,4 @@
-#ifndef SUSPEND_H
-#define SUSPEND_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -13,5 +12,3 @@ void suspend_wakeup_init_user(void);
 void suspend_wakeup_init_kb(void);
 void suspend_power_down_user(void);
 void suspend_power_down_kb(void);
-
-#endif