Make default layer size 16-bit (#15286)

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

keyboards/splitkb/kyria/keymaps/ninjonas/oled.c

@@ -111,7 +111,7 @@ void oled_slash_separator(void){
 
 void render_layout_state(void) {
   oled_write_P(PSTR("Layout: "), false);
-  switch (biton32(default_layer_state)) {
+  switch (get_highest_layer(default_layer_state)) {
       case _COLEMAK:
         oled_write_P(PSTR("Colemak"), false);
         break;