msm: mdss: Add support for direct secure dispaly transition

In the current implementation, during secure to non secure
and non secure to secure transitions, a NULL commit will be
issued by the framework to make sure that the previous settings
are completely cleared. This is not required for command mode
panels, as we can wait for the frame transfer when the transition
happens.

Adding support to wait for the previous frame transfer completion,
during the non secure to secure and vice-versa transitions.

Change-Id: Id17b456b5b0744cff2f53688b7857569e4d257d6
Signed-off-by: Krishna Chaitanya Devarakonda <kdevarak@codeaurora.org>