powerpc/perf: Fix to update cache events with l2l3 events in power10

Export l2l3 events (PM_L2_ST_MISS and PM_L2_ST) and LLC-prefetches
(PM_L3_PF_MISS_L3) via sysfs, and also add these to list of
cache_events.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1606409684-1589-7-git-send-email-atrajeev@linux.vnet.ibm.com