GKlib no longer uses -fPIC + compiler definition NO_X86 breaks arm64 build

[mtjrider]

GKlib no longer compiles with -fPIC, breaking downstream libraries that link to it where symbol relocation is required.
When adding cmake/GKlibSystem.cmake to the include(...)s, the compiler definition NO_X86 breaks arm64 compilation.

My solution was to remove the compiler definition and include cmake/GKlibSystem.cmake, but this may not be ideal.

Pull request: #48
Fork implementing the above: https://github.com/mtjrider/GKlib (please refer to the main branch)