board-msm7x27a: display: Avoid backlight call during suspend

Backlight level is being explicitly set to zero during suspend.
This operation may be fine when the level gets restored to max
value during resume. But, this has been removed earlier to avoid
panel-specific Initialization transients during resume. The
backlight control by various clients like CABL daemon and light
service ensures proper backlight level during resume after the
basic initialization is complete.

In cases like Recovery mode, this creates a problem if the
backlight level is set to zero explicitly during the FB driver's
suspend operations. In this mode, there is no available means to
restore it after resume. Hence, avoiding this operation during
suspend. In normal modes, CABL daemon and other clients will take
care of setting the backlight level to minimum while going to
suspend.

Change-Id: I7f0d0a9690133b04bd72d91ff52f72d60916e8c3
Signed-off-by: Pradeep Jilagam <pjilagam@codeaurora.org>
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>