Simplify GetSysMenuRegion

Source/Core/DiscIO/Enums.cpp

@@ -126,50 +126,15 @@ Country CountrySwitch(u8 country_code)
 
 u8 GetSysMenuRegion(u16 title_version)
 {
-  switch (title_version)
+  switch (title_version & 0xf)
   {
-  case 128:
-  case 192:
-  case 224:
-  case 256:
-  case 288:
-  case 352:
-  case 384:
-  case 416:
-  case 448:
-  case 480:
-  case 512:
+  case 0:
     return 'J';
-  case 97:
-  case 193:
-  case 225:
-  case 257:
-  case 289:
-  case 353:
-  case 385:
-  case 417:
-  case 449:
-  case 481:
-  case 513:
+  case 1:
     return 'E';
-  case 130:
-  case 162:
-  case 194:
-  case 226:
-  case 258:
-  case 290:
-  case 354:
-  case 386:
-  case 418:
-  case 450:
-  case 482:
-  case 514:
+  case 2:
     return 'P';
-  case 326:
-  case 390:
-  case 454:
-  case 486:
-  case 518:
+  case 6:
     return 'K';
   default:
     return 'A';