CMake: Fix cross compilation with libelf
CMake: Fix cross compilation with libelf

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