msm_vidc: mask extra interrupts from video hardware.

video driver was registering to receive all interrupts from video
hardware, so video hardware raised multiple interrupts when
processing a frame. This change masks interrupts which do not convey
video information, thereby reducing the number of times video hardware
interrupts the host.

Change-Id: I861cad7cc217241bb804b808796863f566aedf6c
Signed-off-by: Ashray Kulkarni <ashrayk@codeaurora.org>