Revert "msm_fb: display: Add support for 4 layer MDP composition"

This reverts commit df6a40b2bef4ba7716f96e4f4053085ca6ccdffa.

	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