msm: kgsl: Notify the powerscale governor at state changes

There were a few paths where the powerscale governor was not notified
when the state was changed. Add the required calls so that the state
as seen by the governor is consistent with the state of the device.

CRs-Fixed: 808248
Change-Id: I3167aa1642dd0627fd57c388cbf3d3b9f5444806
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>