msm: vidc: Scale clocks and buses on V4L2_CID_MPEG_VIDC_SET_PERF_LEVEL

The setting of client desired performance level was only applied when a
significant event (e.g. first frame or port reconfig) took place.  The
performance level should apply immediately if client sets V4L2_CID_MPEG\
_VIDC_SET_PERF_LEVEL.

CRs-Fixed: 695396
Change-Id: I467274a594053dc5872faaef7e114def3f4cb173
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>