[OpenMP][libomp] Add core attributes to KMP_HW_SUBSET

Allow filtering of resources based on core attributes. There are two new
attributes added:
1) Core Type (intel_atom, intel_core)
2) Core Efficiency (integer) where the higher the efficiency, the more
   performant the core
On hybrid architectures , e.g., Alder Lake, users can specify
KMP_HW_SUBSET=4c:intel_atom,4c:intel_core to select the first four Atom
and first four Big cores. The can also use the efficiency syntax. e.g.,
KMP_HW_SUBSET=2c:eff0,2c:eff1

Differential Revision: https://reviews.llvm.org/D114901