drm/virtio: Stop updating plane->crtc

We want to get rid of plane->crtc on atomic drivers. Stop setting it.

v2: s/fb/crtc/ in the commit message (Gerd)

Cc: David Airlie <airlied@linux.ie>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180525185045.29689-12-ville.syrjala@linux.intel.comReviewed-by: Sinclair Yeh <syeh@vmware.com>

drivers/gpu/drm/virtio/virtgpu_display.c

@@ -282,8 +282,6 @@ static int vgdev_output_init(struct virtio_gpu_device *vgdev, int index)
 	drm_crtc_init_with_planes(dev, crtc, primary, cursor,
 				  &virtio_gpu_crtc_funcs, NULL);
 	drm_crtc_helper_add(crtc, &virtio_gpu_crtc_helper_funcs);
-	primary->crtc = crtc;
-	cursor->crtc = crtc;
 
 	drm_connector_init(dev, connector, &virtio_gpu_connector_funcs,
 			   DRM_MODE_CONNECTOR_VIRTUAL);