msm: mdss: Adding lcd notifier

Supports notifier for start&end of LCD power on&off

Change-Id: Idaa685a2c554286da5f764519305d830c4d1a1bd
Signed-off-by: Se Hun Kim <sean2.kim@lge.com>
Signed-off-by: Jongrak Kwon <jongrak.kwon@lge.com>
Signed-off-by: Devin Kim <dojip.kim@lge.com>

Conflicts:
	drivers/video/msm/mdss/Makefile
	drivers/video/msm/mdss/mdss_dsi.c

Conflicts:
	drivers/video/msm/mdss/Makefile

Conflicts:
	drivers/video/msm/mdss/Makefile
	drivers/video/msm/mdss/mdss_dsi.c

Conflicts:
	drivers/video/msm/mdss/Makefile
	drivers/video/msm/mdss/mdss_dsi.c
lcd_notify: Only pass display state to lcd_notifer_call_chain
 - We can pass 'NULL' directly to blocking_notifier_call_chain
 - Remove unused struct 'lcd_event'

Conflicts:
	drivers/video/msm/mdss/mdss_dsi.c