Fixup missing include in mxss via keymap (#20475)

keyboards/mxss/keymaps/via/keymap.c

@@ -14,6 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include QMK_KEYBOARD_H
+#include "mxss_frontled.h"
 
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 	LAYOUT_all( /* L0 */