Fix detection of native NDS ARM BIOS images (#1910)

* Fix detection of native NDS ARM BIOS images

- Instead of checking for built-in BIOS images, now the altered methods check for native ones
- The CRC32 must match exactly; patched BIOS images will result in `false`

* Encapsulate `NDS::ARM9BIOS` and `ARM7BIOS`

- Also compute the checksum only when setting the BIOS

src/ARMJIT.cpp

@@ -63,12 +63,12 @@ const u32 CodeRegionSizes[ARMJIT_Memory::memregions_Count] =
     0,
     ITCMPhysicalSize,
     0,
-    sizeof(NDS::ARM9BIOS),
+    ARM9BIOSSize,
     MainRAMMaxSize,
     SharedWRAMSize,
     0,
     0x100000,
-    sizeof(NDS::ARM7BIOS),
+    ARM7BIOSSize,
     ARM7WRAMSize,
     0,
     0,