msm: kgsl: Set requested power state to NONE after resume

When GPU resumes from suspend requested state is not cleared to NONE.
Due to this idle reporting is not done and GPU stays at MAX freq. As
a fix if the current power state is already ACTIVE and request is
made for active power state then clear the requested state immediately.

CRs-fixed: 424682
Change-Id: I7f0d7fa819308f166cbbbf30b2c20aee73644cfb
Signed-off-by: Vinay Roy <vroy@codeaurora.org>