Revert "msm_fb: call the backlight control before FB_BLANK_POWERDOWN"

This reverts commit 05925bc63063f480607a20218e0455afa5574f0b.

Conflicts:
	drivers/video/msm/msm_fb.c
msm: display: add more checking to ensure display is idle

Before execute operation on display, make sure it is complete idle
Because non-blocking display update has been introduced, need make sure
display update has finished in all entrances except the ones for
initialization.

Change-Id: I0660080262b7e5895f5f558c0a9f71aa84b9aa99
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Signed-off-by: Naseer Ahmed <naseer@codeaurora.org>
msm: display: display idle checking update

msm_fb_blank_sub might be called for UNBLANK from
display update work queue, which is at commit state.
Idle detection is invalid in this situation
Add detection for external snd earlyuspend/resume interface.

Signed-off-by: Ken Zhang <kenz@codeaurora.org>