drm/amdgpu: don't call drm_connector_register for non-MST ports

The core does this for us now.
Tested-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c

@@ -1931,7 +1931,6 @@ amdgpu_connector_add(struct amdgpu_device *adev,
 		connector->polled = DRM_CONNECTOR_POLL_HPD;
 
 	connector->display_info.subpixel_order = subpixel_order;
-	drm_connector_register(connector);
 
 	if (has_aux)
 		amdgpu_atombios_dp_aux_init(amdgpu_connector);

drivers/gpu/drm/amd/amdgpu/dce_virtual.c

@@ -609,7 +609,6 @@ static int dce_virtual_connector_encoder_init(struct amdgpu_device *adev,
 	connector->display_info.subpixel_order = SubPixelHorizontalRGB;
 	connector->interlace_allowed = false;
 	connector->doublescan_allowed = false;
-	drm_connector_register(connector);
 
 	/* link them */
 	drm_connector_attach_encoder(connector, encoder);

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

@@ -5972,7 +5972,6 @@ static int amdgpu_dm_connector_init(struct amdgpu_display_manager *dm,
 	drm_connector_attach_encoder(
 		&aconnector->base, &aencoder->base);
 
-	drm_connector_register(&aconnector->base);
 #if defined(CONFIG_DEBUG_FS)
 	connector_debugfs_init(aconnector);
 	aconnector->debugfs_dpcd_address = 0;