msm: kgsl: Always set the active powerlevel when changing clock rates

kgsl_pwrctrl_pwrlevel_change might be called when clocks are on or off.
If clocks are off we don't step the clock rate and the active_pwrlevel
won't be set to the new and correct level.  Set active_pwrlevel to its
new level before doing anything else.

Change-Id: Ic0dedbad84ce1cc1b3b8df97df32e39686b85671
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>