Add frontier mon constants

src/battle_tower.c

@@ -24,6 +24,7 @@
 #include "tv.h"
 #include "battle_factory.h"
 #include "constants/battle_frontier.h"
+#include "constants/battle_frontier_mons.h"
 #include "constants/battle_tower.h"
 #include "constants/frontier_util.h"
 #include "constants/items.h"