mdss: mdp: do not send panel events for idle power collapse

When mdss idle power collapse is enabled, panel suspend and resume
events should not be sent to ensure that panel drivers remain active.

Change-Id: Ifbcdee69432cbd0d30f16c86af9c126d9443e269
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>