msm: camera: Add support for DPCM modes

DPCM8 and DPCM6 are 10 bit to 8 and 10 bit
to 6 bit compression formats respectively
which sensor outputs and it is decompressed
to 10 bit in CSID

Change-Id: I8ec4de7d9cfa5e9c86d97bd9cb81feddc97dc7b8
Signed-off-by: Vijay kumar Tumati <vtumati@codeaurora.org>