Include gba/defines.h in gba/types.h (#4364)

If gba/types.h is included before gba/defines.h, it ends up declaring a
variable named PACKED rather than specifying that BgCnt should be
packed.

include/gba/types.h

@@ -2,6 +2,7 @@
 #define GUARD_GBA_TYPES_H
 
 #include <stdint.h>
+#include "gba/defines.h"
 
 typedef uint8_t   u8;
 typedef uint16_t u16;