Gfx-Display: postpone hdmi encoder restore

Gfx-Display: postpone hdmi encoder restore

BZ: 38178

after late resume, both mipi and hdmi are enabled, and lock screen should be
displayed. while actually an intermediate picture is showed before showing lock
screen. the reason is there is a early_suspend callback for fb device, a thread
loop in framework check its status to see whether fb device is ready to draw.
its level is 100, but the level of gfx_early_suspend is 150. so in early
suspend, the sequence is stop_drawing_early_suspend() --> gfx_early_suspend(),
while in late_resume, the sequence is gfx_late_resume() -->
start_drawing_late_resume(). so the first flip happens after enable pipe and
plane.

the solution is:
1. for mipi, before enabling pipe and plane, restore a black framebuffer.
2. for hdmi, postpone enable hdmi plane to let flip happen fist.

Change-Id: Ib15e72b24d02de97d4f8928afbcbb9fc24743ebd
Signed-off-by: Geng Xiujun <xiujun.geng@intel.com>
Reviewed-on: http://android.intel.com:8080/51373
Reviewed-by: Xu, Randy <randy.xu@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: Ai, Ke <ke.ai@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>