qcom/l2cache_counters: Enable event creation for any cluster

If all the cpu's in a cluster are offline, pmu events are not
getting created for offline/inactive cluster. As the counter
registers are memory mapped, pmu event enable/read for
offline/inactive cluster, should be allowed from an online
cpu in online/active cluster. Once a cpu comes back online
from offline/inactive cluster, migrate cluster pmu events.

Change-Id: I653b15f44ecf98be54da272c350e28e769c0a24e
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>