msm: camera: isp: Fix drop frame due to reg update miss

In few scenarios, where the register update ioctl is
missed, the handling of frame drop is not working
in such scenarios as the frame drop pattern is not
set correctly. Once the epoch handling is done,
we need to re-configure the buffer and pattern..

Change-Id: I87b2cecda7e7e1addc68511dad6a80498051f87a
Signed-off-by: Meera Gande <mgande@codeaurora.org>