drm/amdgpu: Remove drm_fb_helper_{add,remove}_one_connector calls

drm_fb_helper_{add,remove}_one_connector() are dummy functions now
and serve no purpose. Hence remove their calls.

This is the preparatory step for removing the
drm_fb_helper_{add,remove}_one_connector() functions from
drm_fb_helper.h

Signed-off-by: Pankaj Bharadiya <[e-mail]>
Reviewed-by: Emil Velikov <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

···
 static void dm_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_connector *connector)
 {
-	struct amdgpu_dm_connector *master = container_of(mgr, struct amdgpu_dm_connector, mst_mgr);
-	struct drm_device *dev = master->base.dev;
-	struct amdgpu_device *adev = dev->dev_private;
 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
 
 	DRM_INFO("DM_MST: Disabling connector: %p [id: %d] [master: %p]\n",
···
 	}
 
 	drm_connector_unregister(connector);
-	if (adev->mode_info.rfbdev)
-		drm_fb_helper_remove_one_connector(&adev->mode_info.rfbdev->helper, connector);
 	drm_connector_put(connector);
 }
 
 static void dm_dp_mst_register_connector(struct drm_connector *connector)
 {
-	struct drm_device *dev = connector->dev;
-	struct amdgpu_device *adev = dev->dev_private;
-
-	if (adev->mode_info.rfbdev)
-		drm_fb_helper_add_one_connector(&adev->mode_info.rfbdev->helper, connector);
-	else
-		DRM_ERROR("adev->mode_info.rfbdev is NULL\n");
-
 	drm_connector_register(connector);
 }