openmp: Exclude powerpc
openmp: Exclude powerpc

ppc is not yet supported by openmp
see https://github.com/llvm/llvm-project/blob/main/openmp/runtime/cmake/LibompGetArchitecture.cmake#L16

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

kraj/meta-clang,kraj/meta-clang,kraj/meta-clang