Revert "Revert "msm_fb: display: Add backlight with first pan display after resume""

This reverts commit f2c6423bfc0c89c251376a4e6e3c26e4c573f56b.
video: msm: Add user-defined backlight scaling

Add method for scaling backlight based off of a user provided ratio and
minimum level for the scaling to be applied.

Change-Id: I74c2329c842dd9cbbc9eddfff38cd56fd0e939a4
Signed-off-by: Carl Vanderlip <carlv@codeaurora.org>
(cherry picked from commit f0fd8e7323ea0f60539918528a4cfa1edb39b828)

Conflicts:
	drivers/video/msm/msm_fb.c
	include/linux/msm_mdp.h
Revert "Revert "video: msm_fb: Ensure backlight is scaled atomically""

This reverts commit 6aa1461f40f4cbe60f8b1df038985f0cd30391cf.