msm_fb: display: Add support for 4 layer MDP composition

Add 4 layers composition support to MDP by allowing borderfill
pipe to be used as base layer of mdp blending. This releases
RGB1 base pipe which can be used as a general purpose pipe.

Change-Id:I517485d738e8bb555a263b3ea885d78d5e4f4396
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>

committer	Giulio Cervera <giulio.cervera@gmail.com>

LINK TO SOURCE: https://android.googlesource.com/kernel/msm/+/667554980deee31151c5349d64405b3ee8cd7ca2
	modified:   drivers/video/msm/mdp.c
	modified:   drivers/video/msm/mdp.h
	modified:   drivers/video/msm/mdp4.h
	modified:   drivers/video/msm/mdp4_overlay.c
	modified:   drivers/video/msm/mdp4_overlay_dsi_cmd.c
	modified:   drivers/video/msm/mdp4_overlay_dsi_video.c
	modified:   drivers/video/msm/mdp4_overlay_dtv.c
	modified:   drivers/video/msm/mdp4_overlay_lcdc.c
	modified:   drivers/video/msm/mdp4_util.c
	modified:   drivers/video/msm/mdp_debugfs.c
	modified:   include/linux/msm_mdp.h