msm: mdss: fix vsync ctrl logic during suspend/resume

Sometimes vsync ctrl ioctl can happen before panel is on after resume,
in this case driver needs to remember state of vsync ctrl and apply
after resume.

Change-Id: Ia583bd9e3a858c5972623eae0512fa27da8452e1
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>