drm: remove all control node code

With the ioctl and driver prep done, we can remove everything else.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20180420065159.4531-4-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 1c5b5ce..b3c1daa 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -331,9 +331,7 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 	struct device *kdev;
 	int r;
 
-	if (minor->type == DRM_MINOR_CONTROL)
-		minor_str = "controlD%d";
-	else if (minor->type == DRM_MINOR_RENDER)
+	if (minor->type == DRM_MINOR_RENDER)
 		minor_str = "renderD%d";
 	else
 		minor_str = "card%d";