sdm: PowerOff crtc before cleaning up display.

On display disconnect, trigger a commit with
crtc disable before destroying display object.

Change-Id: I58bd8cb73686f937f284e8f1fc849a66254b293c
CRs-fixed: 2062189
diff --git a/sdm/libs/core/drm/hw_device_drm.cpp b/sdm/libs/core/drm/hw_device_drm.cpp
index b244a2a..9e99361 100644
--- a/sdm/libs/core/drm/hw_device_drm.cpp
+++ b/sdm/libs/core/drm/hw_device_drm.cpp
@@ -356,6 +356,7 @@
 }
 
 DisplayError HWDeviceDRM::Deinit() {
+  PowerOff();
   delete hw_scale_;
   registry_.Clear();
   drm_mgr_intf_->DestroyAtomicReq(drm_atomic_intf_);