Fix MMC3 bank mirroring

src/map/mmc3.c

@@ -38,7 +38,7 @@ typedef struct {
 } mmc3_mapper;
 
 static inline uint8_t* mmc3_prg_bank(mmc3_mapper* map, int bank) {
-    return &map->prg_rom[bank << 13];
+    return &map->prg_rom[(bank % map->prg_rom_banks) << 13];
 }
 
 static inline void mmc3_map_prg(mmc3_mapper* map,
@@ -61,7 +61,7 @@ static inline void mmc3_update_prg(mmc3_mapper* map,
 }
 
 static inline uint8_t* mmc3_chr_bank(mmc3_mapper* map, int bank) {
-    return &map->chr_rom[bank << 10];
+    return &map->chr_rom[(bank % map->chr_rom_banks) << 10];
 }
 
 static inline void mmc3_map_2k_chr(mmc3_mapper* map,