msm: camera: invalidate cached buffers before sending to hardware

Since the buffers are now allocated in cached mode they
need to be cache-invalidated before hardware writes new
data into them. This prevents the CPU from reading stale data
from the cache. Also, if hardware reads a CPU modified buffer, the
data needs to be cache-cleaned or written back before hardware
reads from it. An example here is gemini reading a post-processed
buffer for JPEG encoding.

Change-Id: I8b4598f7984b8292bcc7ed1cc8d7ac03dd7365a8