msm: vidc: Remove unnecessary scale clocks

Clock scaling is being called for every command
queuing to venus firmware unnecessarily. Remove
it from command queue functionality and add in
power enable function to set correct clock rate
when venus resumed from power collapse.

Change-Id: I29eea6b2b27696176bf5f0c9f7700a8c3441533c
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>