msm: camera2: Enhance cpp driver

The cpp driver is enhanced to store the buffer mapping info. This
helps to get vb2 buffers directly from vb2 queue in kernel space.
The redundant queues in cpp kernel driver is removed as because
the userspace streamlines the priority based queue.

Change-Id: I304c1b929f73331f89b7ac666222156b9f3e9063
Signed-off-by: Rajakumar Govindaram <rajakuma@codeaurora.org>