msm: camera: Add Bayer stats support for vfe40

1.Implement correct stats logic for 8974 bayer stats support.
2.Modify UB buffer config for 8974.
3.Add frame subsample and irq subsample support for 8974 bayer stats.

Change-Id: I1ade40e5781868171d138b4ba79afc9b9ef61a9d
Signed-off-by: Peter Liu <pingchie@codeaurora.org>
3 files changed