GB: Fix timer resetting
GB: Fix timer resetting

Anty-Lemon/mgba,jeremyherbert/mgba,jeremyherbert/mgba,mgba-emu/mgba,mgba-emu/mgba,mgba-emu/mgba,Anty-Lemon/mgba,sergiobenrocha2/mgba,sergiobenrocha2/mgba,libretro/mgba,Iniquitatis/mgba,fr500/mgba,Touched/mgba,Anty-Lemon/mgba,MerryMage/mgba,libretro/mgba,iracigt/mgba,iracigt/mgba,fr500/mgba,fr500/mgba,Touched/mgba,sergiobenrocha2/mgba,Touched/mgba,sergiobenrocha2/mgba,Iniquitatis/mgba,Anty-Lemon/mgba,sergiobenrocha2/mgba,fr500/mgba,MerryMage/mgba,iracigt/mgba,libretro/mgba,libretro/mgba,iracigt/mgba,Iniquitatis/mgba,MerryMage/mgba,mgba-emu/mgba,libretro/mgba,jeremyherbert/mgba,jeremyherbert/mgba,Iniquitatis/mgba