LCD: GRAM refresh patch

This patch is added for gram-embedded device like mddi.
because, when suspend state, power of mddi is off usually,
gram of DDI chip has garbage data until data of gram is refreshed.
this can cause displaying broken screen in time of turning backlight on.
for preventing this problem, add refreshing routine before turning
backlight on by using late resume mechanism.

Before: Push last fb data to GRAM
After: Push 0-initialized data to GRAM

Change-Id: Ia35283b50b2b1b39957b7c493cec31fda95c820b
Signed-off-by: Rashed Abdel-Tawab <rashedabdeltawab@gmail.com>