msm: camera: Add uapi definitions for camera reg dump

For debugging, there are a set of register values that user
space needs. Based on the offset and range given, values can
be dumped into an out buffer to be further processed. Add
uapi support for this reg dump.

Change-Id: I6e6f89625a505158a6bf8932ebb9d0ae78bf0129
Signed-off-by: Mukund Madhusudan Atre <matre@codeaurora.org>