msm: camera: isp: Add VFE Parent probe and common data

Make header changes for structures/defines to enable unified probe. Make
provision for shared data between 2 HW. Define IOCTL for setting master
and slave HW. Create separate probe methods for parent and child nodes.
Link common_data to all child nodes. Create module and driver in
msm_ispxx.c files.
This framework enables the parent device to control both HW
to achieve better sync and the common data enables sharing of data
between 2 HW.

Change-Id: Ic3ac8151ed6a89e3934b1cd2429261beec6f0c04
Signed-off-by: Harsh Shah <harshs@codeaurora.org>
Signed-off-by: Peter Liu <pingchie@codeaurora.org>