msm: kgsl: Do not use kgsl_pwrctrl_pwrlevel_change from gmu_start

Do not use kgsl_pwrctrl_pwrlevel_change from gmu_start to vote
for default power level. This is because this function doesn't
change the power level in cases where last active_pwrlevel is
equal to default power level. Using this results in no vote at
GPU wake up causing performance issues.

This change adds a new function kgsl_gmu_gpu_pwrlevel_change
to vote for GPU power level from gmu_start to fix above issue.

Change-Id: I636bd6dc7958a90db5dc1d90e0489e472b709525
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>