msm: camera: Multi module support in sensor architecture.

In current sensor architecture, one platform device is created for
every sensor defined in dtsi for that platform. It creates redundancy
since only one camera can be connected in camera slot for particular
target. To avoid this redundancy, create platform device for every
camera slot for that platform and probe using single compatible name
"qcom,camera" for all drivers. Add sensor utility functions to be
used by all camera sensors.

Change-Id: I135bda007f8eec2f339a6b3dbf1116c5ab600b94
Signed-off-by: Sreesudhan Ramakrish Ramkumar <srramku@codeaurora.org>
Signed-off-by: Evgeniy Borisov <eborisov@codeaurora.org>
Signed-off-by: Vasko Kalanoski <vaskok@codeaurora.org>
(cherry picked from commit 2e31f9d73a4f72d23cb5d9f5d81767cca678fa05)
(cherry picked from commit e052ef266ffe4848800d8cbd82d516d98bf5aa9f)

Signed-off-by: Satish Kamuju <skamuj@codeaurora.org>