msm: vidc: Apply a QOS vote when Venus is active

During video playback, L2 power collapse is occurring far too often to
actually save power.  As such, apply a vote to prevent L2 PC from
occurring.

Change-Id: I1d86b47a1ed9dffb02d099d3158892bf99ed955e
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>