perf vendor events: Update POWER9 events

Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20180313224647.GA22960@us.ibm.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>