selftests/powerpc/pmu: Add test for hardware cache events

selftests/powerpc/pmu: Add test for hardware cache events

The testcase checks if the transalation of a generic hardware cache
event is done properly via perf interface. The hardware cache events has
type as PERF_TYPE_HW_CACHE and each event points to raw event code id.

Testcase checks different combination of cache level, cache event
operation type and cache event result type and verify for a given event
code, whether transalation matches with the current cache event mappings
via perf interface.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610134113.62991-36-atrajeev@linux.vnet.ibm.com