lang/intel-compute-runtime: track libva dependency

• Checking for module 'libva>=1.0.0'
• Found libva, version 1.7.0
• Looking for vaGetLibFunc in va
• Looking for vaGetLibFunc in va - found
• Using libva
• LibVA include dirs: /usr/local/include

$ strings /usr/local/lib/intel-opencl/libigdrcl.so | grep '^va[A-Z]'
vaDestroyImage
vaSyncSurface
vaDeriveImage
vaMaxNumImageFormats
vaGetLibFunc
vaQueryImageFormats
vaDisplayIsValid