GBA: Fix typo of GBAIsBIOS
GBA: Fix typo of GBAIsBIOS

libretro/mgba,Iniquitatis/mgba,fr500/mgba,fr500/mgba,libretro/mgba,mgba-emu/mgba,Iniquitatis/mgba,libretro/mgba,Anty-Lemon/mgba,Anty-Lemon/mgba,Anty-Lemon/mgba,libretro/mgba,mgba-emu/mgba,libretro/mgba,Iniquitatis/mgba,mgba-emu/mgba,fr500/mgba,Iniquitatis/mgba,Anty-Lemon/mgba,fr500/mgba,mgba-emu/mgba