disp: msm: sde: update crtc check in drm_check_dpms

In cases of adb shell stop, connector->state->crtc is
not updated which prevents panel power down
notification to be sent. In such cases updated crtc
from old connector state.

Change-Id: I94f9e5ad469d771cc673123b4e0cc65ea8f4653e
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>
Signed-off-by: Narendra Muppalla <NarendraM@codeaurora.org>