mupen64plus-libretro: fix cc compilation abort 

Fix issue 492. cc aborts compilation if there is not enough memory. cc needs up to 310MB. Retropie 2.3 SD Card image: Raspbian + daemons need 110MB. 
https://github.com/petrockblog/RetroPie-Setup/issues/492
mupen64plus-libretro: copy game specific config files...

...to RetroPie/BIOS path.
Merge pull request #493 from gizmo98/patch-2

mupen64plus-libretro: fix cc compilation abort