msm: vidc: Offload interframe clock gating to client

This commit removes the interframe clock gating that is done when Venus
reponds with a FBD. The motivation for removing this feature is because
the gating logic depends heavily upon the timestamp which might be
incorrect depending on the content.  Instead, the driver will now depend
on the client correcting the FPS occasionally via VIDIOC_S_PARM.

The commit also introduces some fixes in the handling of s_parm,
particularly with timestamp operations which should be done using 64 bit
types.

Change-Id: I648f4c91c3fce5acb9f29d8791bb43147b33e1cf
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>