msm: camera: use devicetree for getting clock info in CPP

CPP needs to use devicetree node to read the clock information.
This is required because, different targets may use different
set of clocks and this change is needed to  help maintain a
generic CPP driver. Fix minor compilation warning in vpe driver.

Change-Id: I641f5051564253691da9dd0e6f45b7617f5cc2e3
Signed-off-by: Punit Soni <punits@codeaurora.org>