Copy Berry Fix MB dism from FR (#777)

* Copy Berry Fix MB dism from FR

berry_fix/payload/include/rtc.h

@@ -0,0 +1,15 @@
+#ifndef GUARD_RTC_H
+#define GUARD_RTC_H
+
+#include "gba/gba.h"
+#include "siirtc.h"
+#include "global.h"
+
+extern struct Time gTimeSinceBerryUpdate;
+extern struct Time gRtcUTCTime;
+
+bool32 rtc_maincb_is_rtc_working(void);
+bool32 rtc_maincb_is_time_since_last_berry_update_positive(u8 *);
+void rtc_maincb_fix_date(void);
+
+#endif //GUARD_RTC_H