msm: camera: Reorganize the camera io functions.

- Reorganize camera io functions by putting all the
  common APIs in the util file.
- Move all the hardware
  specific IO files into the io folder.
- The io functions used by the camera driver are named
  as msm_io_* even though they are camera specific.
  Rename them to msm_camera_io_*.

CRs-Fixed: 350209
Change-Id: I5be9a000ee7f9506ae921233196f3507a9ebb095
Signed-off-by: Kiran Kumar H N <hurlisal@codeaurora.org>