drm/amdgpu/virtual_dce: add vega12 support

Add virtual dce support for vega12.
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NFeifei Xu <Feifei.Xu@amd.com>

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

@@ -473,6 +473,7 @@ static int dce_virtual_hw_init(void *handle)
 		/* no DCE */
 		break;
 	case CHIP_VEGA10:
+	case CHIP_VEGA12:
 		break;
 	default:
 		DRM_ERROR("Virtual display unsupported ASIC type: 0x%X\n", adev->asic_type);