msm: vidc: Use msm_fw_low_power_mode as footswitch for power collapse

For debugging purposes it's often useful to turn off hardware power
collapse. Currently we use msm_fw_low_power_mode as a footswitch for
disabling s/w power collapse.  Use it for h/w power collapse as well.

Change-Id: I518dd231c3e560b67dbea9e90ea43dcf6752b5ff
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>