perf vendor events power10: Add metric events JSON file for power10 platform

Add PMU metric JSON file for power10 platform.
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Paul Clarke <pc@us.ibm.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/lkml/20211108060010.177517-1-kjain@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>