msm: vidc: update current value while updating the v4l controls

A v4l control has current and new value. Current value indicates the
permanent value and any change in the control should be reflected to
current value. V4l client should ensure that while updating the
new value, current value is updated as well. If current value is
updated by v4l framework, its good, otherwise, the v4l driver should
update it.

Change-Id: Id0730465487dc4175516f4ef460758bee0b76308
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>