msm: camera: Implement reading SOC_HW_VER reg

Add implementation to support reading
SOC_HW_VERSION registers for vfe needs.
Add tcsr_soc_hw_version register address
in dts file. Both 8974 and 8x26 family
support that register. 8x10 does not
support it. VFE need this register to
determine difference between 2.1 and 2.2
hardware version. VFE version remain
the same for both hardwares.

Change-Id: I096bcc16f150a2b2f50c5f60ec0ab0ec957d0cdf
Signed-off-by: Slavi Dimitrov <slavid@codeaurora.org>