Add some battle frontier constant usage

include/constants/battle_frontier.h

@@ -1,6 +1,8 @@
 #ifndef GUARD_CONSTANTS_BATTLE_FRONTIER_H
 #define GUARD_CONSTANTS_BATTLE_FRONTIER_H
 
+#include "constants/pokemon.h"
+
 #define FRONTIER_CHALLENGE(facility, mode) ((facility << 8) + mode)
 
 // Battle Frontier facility ids.
@@ -46,6 +48,14 @@
 #define MAX_BATTLE_FRONTIER_POINTS 9999
 #define MAX_STREAK 9999
 
+#define FRONTIER_MAX_LEVEL_50   50
+#define FRONTIER_MIN_LEVEL_OPEN 60
+#define FRONTIER_MAX_LEVEL_OPEN MAX_LEVEL
+
+// This is the default number of battles (or floors, in Battle Pyramid) per challenge.
+// There are 2 facilities that differ: Battle Dome (DOME_ROUNDS_COUNT) and Battle Pike (NUM_PIKE_ROOMS).
+#define FRONTIER_STAGES_PER_CHALLENGE 7
+
 // These sets of facility ids would be redundant if the order was consistent
 // The order is important for this set so that all the non-link records can be continuous
 #define RANKING_HALL_TOWER_SINGLES   0