msm: mdss: add retire fence support

Retire fence timeline should follow the actual panel vsync more closely.
For video mode the retire fence can be signaled along with the release
timeline with +1 offset, since this is signaled at vsync.
In case of command mode the panel vsync can be different from buffer
release timeline. To handle the command mode panel vsyncs better, create
a new timeline for the retire fence signaling.

Change-Id: If8a1eb717d733ca215275a8be4f0054091dbc147
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>

Conflicts:
	drivers/video/msm/mdss/mdss_fb.c
	drivers/video/msm/mdss/mdss_mdp_overlay.c