msm: camera: isp: Avoid overflow processing during reset

During device reset, status bits may contain spurious interrupts.
Avoid servicing these spurious interrupts during reset pending. Also,
clear all stats bits before calling reset.

Change-Id: Ied4e8647281570bb6b6aceabbd49e59ef6053371
Signed-off-by: Alok Kediya <kediya@codeaurora.org>