lib/intel_compute: Migrate xe_compute library to intel_compute

During my work on adding xe-compute support to DG2 I hit some issues
on Xe driver so instead of limiting workload to Xe only I decided to
handle i915 as well. Such attitude might be handy on driver feature
status comparison.

Patch does preparation step to share the code between i915 and Xe.

v2: Add intel_ prefix as compute code is in the library and globally
    visible (Kamil)

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Cc: Christoph Manszewski <christoph.manszewski@intel.com>
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>