msm: camera: Support different clock rate for back and front camera

Currently, we use static memory for storing clocks and clock rates.
Hence, only one clock rate can be support for both back and front
camera. Support different clock rate for back and front camera by
allocating memory separately.

Change-Id: I828b4f260f333794097adb461ca150970bf5e3c3
Signed-off-by: Sreesudhan Ramakrish Ramkumar <srramku@codeaurora.org>