msm:camera:icp: Creating separate timer workqueue

Creating separate workqueue for timer to avoid race condition
that can arise if second acquire gets delayed and timer watchdog
bites.

Change-Id: Ib1b3f307027dbd4369dfc57e3cb3ae952b4d96f9
Signed-off-by: Alok Pandey <akumarpa@codeaurora.org>