Fix functions with empty params (#19647)

* Fix functions with empty params

* Found a bunch more

keyboards/planck/keymaps/handwired_binaryplease/keymap.c

@@ -280,13 +280,13 @@ void matrix_init_user(void) {
 
 #ifdef AUDIO_ENABLE
 
-void startup_user()
+void startup_user(void)
 {
     _delay_ms(20); // gets rid of tick
     PLAY_SONG(tone_startup);
 }
 
-void shutdown_user()
+void shutdown_user(void)
 {
     PLAY_SONG(tone_goodbye);
     _delay_ms(150);