drm/msm/sde: enable backlight in ESD recovery case

In case of ESD recovery display disable/enable happens
without the knowledge of backlight framework. So backlight
does not change during this period. This causes issues
where panel used DCS backlight update method where backlight
is lost during ESD trigger and it is not set again after
recovery is complete. This change fixes the issue by
calling backlight update API during ESD recovery display
enable/disable case.

Change-Id: I157120688603dd0558b773bbf41996b6d7373d94
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>