msm: camera: isp: Prevent event processing during overflow

In case of hw error, we should not process camif events.
This change is to prevent processing sof epoch rup and eof
event if overflow_pending flag is ON.

CRs-Fixed: 2694908
Change-Id: Iefb552dbcf550727227493b1d5894ef1a7d07533
Signed-off-by: Ayush Kumar <ayushkr@codeaurora.org>