msm: kgsl: allow clock set options during state transitions for A702

Add control to enable and disable memory retention for clocks in A702.
For nap enabled targets like A702, it is required to have memory
retention enabled for the core clock during nap. Retention can be disabled
during slumber.

Change-Id: Iea5044667ce1fde361ba7dec8797142b8f1d504e
Signed-off-by: Puranam V G Tejaswi <pvgtejas@codeaurora.org>