msm: kgsl: Toggle loop_en while disabling gx gdsc

When all sensors on GFX rail are bypassed/clamped in a certain window
after voltage settling it could cause CPR measurements to stall.
Toggle the loop_en bit, across disabling the gx gdsc, with a delay of
10 XO cycles before disabling gx gdsc.

Change-Id: I44ada515066c601a34f10993677195502fc9e341
Signed-off-by: Raghu Ananya Arabolu <rarabolu@codeaurora.org>