msm: vidc: Vote for DDR BW before FW download

Vote for DDR bandwidth before downloading video
firmware so that as soon as hardware is brought
out of reset it is able to access firmware. Not
doing this might result in IOMMU page faults
on starting video playback or recording.

Change-Id: I91ecdcdc4c57765f848f75ae6f476cee46a16829
Signed-off-by: Vinay Kalia <vkalia@codeaurora.org>