msm: camera: Add support for stats buffer enqueue

ISP statistics buffers are sent to userspace for processing
and need to be enqueue back to kernel.

This change set the buffer to dispatched state before sending
userspace notification and add check to prevent the buffer
from mapping after when it is queue back to kernel.

Change-Id: Icda26f087be80666de8fd5d94f6e0bcb6690fd07
Signed-off-by: Kevin Chan <ktchan@codeaurora.org>
2 files changed