3DS: Add log handler
3DS: Add log handler

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