msm: kgsl: Restart a6xx gpu only once

Currently, as part of fault recovery, we try to
restart the a6xx gpu five times. This loop is
for legacy reasons for a hardware condition that
existed on a4xx. That doesn’t exist for a6xx so
remove the loop. Also, if there are no need to keep
GPU active, we should transition back to SLUMBER.

Change-Id: Ib6f7437bab2b424c4f632efca459ff8c3fd064e4
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>