msm: camera: VFE 4.0 bring up changes

Add IOMMU changes to register device context with camera domain.
Update register address and bit fields for VFE 4.0 for
bayer stats modules and some status registers.
Update driver to support concurrent camera feature, the changes are
mainly to separate the controls of VFE pixel path and RDI path.
AXI write masters are also control separately to start/stop
pixel and RDI paths.

Change-Id: I292efe95ce4ed4b193de95a0f836681ed4d34a14
Signed-off-by: Kevin Chan <ktchan@codeaurora.org>