msm: isp: Clear irq status if irq is set again with same value

Sometimes HW is giving same irq twice even after clearing
irq. As workaround HW team suggested to read back irq
after clearing and if read back irq is same as before clear
then we need to clear register again.

Change-Id: I79cecfa1c61c6224b8f9cef8146a2bb44a7522e8
Signed-off-by: Shilpa Mamidi <shilpam@codeaurora.org>