GB MBC: Fix SRAM sizes 4 and 5

CHANGES

@@ -10,6 +10,7 @@ Bugfixes:
  - GB Video: Fix dot clock timing being slightly wrong
  - GB MBC: Pocket Cam memory should be accessible without enabling
  - GB Memory: Initialize peripheral pointers
+ - GB MBC: Fix SRAM sizes 4 and 5
 Misc:
  - GBA Timer: Use global cycles for timers
  - GBA: Extend oddly-sized ROMs to full address space (fixes mgba.io/i/722)

src/gb/mbc.c

@@ -110,6 +110,12 @@ void GBMBCInit(struct GB* gb) {
 		case 3:
 			gb->sramSize = 0x8000;
 			break;
+		case 4:
+			gb->sramSize = 0x20000;
+			break;
+		case 5:
+			gb->sramSize = 0x10000;
+			break;
 		}
 
 		if (gb->memory.mbcType == GB_MBC_AUTODETECT) {