msm: kgsl: Use spinlock for A6xx perfcounter updates

Add flag ADRENO_PERFCOUNTER_GROUP_RESTORE for perfcounters that
need to be restored for IFPC and preemption.
For these perfcounters
a) get spinlock
b) update the CP powerup restore list
c) update perfcounter select register
d) release spinlock.
Spinlock prevents race condition where GPU might be restoring
these registers while CPU is updating them at the same time.

Change-Id: I3d902d5cdc8c5b69a86353a944c07c9151b42654
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>