msm: camera: Add composite 3 support for VFE

VFE composite irq 3 is listen by camera microcontroller,
in order to update certain vfe registers at frame boundary
in dual VFE use case. This irq is only needed for the VFE
recieving the last pixel of the sensor output image.

Change-Id: I134221d8fad634cee3b28abbd0ad28df922861d2
Signed-off-by: Kevin Chan <ktchan@codeaurora.org>