drm/msm/sde: avoid drm_wait_one_vblank api during pm resume

During pm suspend, pm resume and dual display scenario, 2 crts
are queued on the same display kworker thread. So, drm_wait_one_vblank
api may not call vblank_ctrl_worker until current work is completed
leading to warning. To avoid this scenario detect this condition and
instead wait for 34 ms.

Change-Id: I8734f549b4046702ba820321311f5992832ac759
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>
Signed-off-by: Xiaowen Wu <wxiaowen@codeaurora.org>