GBA Audio: Only increase channel 4 interval
GBA Audio: Only increase channel 4 interval

libretro/mgba,libretro/mgba,Iniquitatis/mgba,mgba-emu/mgba,libretro/mgba,mgba-emu/mgba,Iniquitatis/mgba,libretro/mgba,mgba-emu/mgba,libretro/mgba,mgba-emu/mgba,Iniquitatis/mgba,Iniquitatis/mgba