msm: vdec: configure latency mode for decode session

Static - Enable latency hint which indicates that the
decode session may go into low latency mode during the
session. With this configuration, video driver disables
DCVS and decode batching.
Dynamic - Enable or disable low latency mode during the
session. Based on it, video driver would decide the work
mode and set the same.

Change-Id: If6e85b7adb1bbe4b4bec9e4a8671db64f240cfe8
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>