powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events

Similar to POWER8, POWER9 can count run cycles and run instructions
completed on more than one PMU.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>