Make default layer size 16-bit (#15286)

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

keyboards/ergodox_ez/keymaps/nfriend/keymap.c

@@ -1057,7 +1057,7 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
 }
 
 layer_state_t layer_state_set_user(layer_state_t state) {
-    uint8_t layer = biton32(state);
+    uint8_t layer = get_highest_layer(state);
 
     ergodox_board_led_off();
     ergodox_right_led_1_off();