msm: mdss: Returning NOTIFY_SUSPEND while polling NOTIFY_UPDATE

mdss_fb_update_notify does not return Suspend in NOTIFY_UPDATE
case. Daemon polls on NOTIFY_UPDATE but does not get Suspend
notification. Hence Daemon would not stop polling.

Suspend Case is added in UPDATE case.

Change-Id: Iaeaf819a6849acda2eb7eb78f0fc3306866d1b64
Signed-off-by: Krishna Chaitanya Parimi <cparimi@codeaurora.org>