Fix compilation issue, using Intel OneAPI on Linux

[pablo-benito]

Feature or improvement description

On Linux, using the Intel OneAPI compilers, the compilation process fails with this message:

ld: ../map/libmapcpplib.a(mapinit.c.o): relocation R_X86_64_32S against `.rodata.str1.1' can not be used when making a shared object; recompile con -fPIC
/usr/bin/ld: failed to set dynamic section sizes: bad value
make[2]: *** [modules/openfast-library/CMakeFiles/openfastlib.dir/build.make:128: modules/openfast-library/libopenfastlib.so] Error 1

The -fPIC flag is needed on Unix platforms, regardless the compiler used (GNU or Intel).

Related issue, if one exists

None

Impacted areas of the software

None

Additional supporting information

Test results, if applicable

None