msm: kgsl: Clocks should be set to the active level during NAP

Fix a bug in the interaction between NAP and GPU DCVS.  Without
this change the clock freq recommended by DCVS might or might
not have been used.  Power levels should be stabilized for test
cases now.

Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>