drm/fb-helper: Remove drm_fb_helper add, add_all and remove connector functions

drm_fb_helper_single_add_all_connectors(),
drm_fb_helper_add_one_connector()
and drm_fb_helper_remove_one_connector() don't keep an array of
connectors anymore and are just dummy. Now we have no callers to these
functions hence remove them.
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305120434.111091-7-pankaj.laxminarayan.bharadiya@intel.com

include/drm/drm_fb_helper.h

@@ -451,27 +451,6 @@ drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
 
 #endif
 
-/* TODO: There's a todo entry to remove these three */
-static inline int
-drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
-{
-	return 0;
-}
-
-static inline int
-drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
-				struct drm_connector *connector)
-{
-	return 0;
-}
-
-static inline int
-drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
-				   struct drm_connector *connector)
-{
-	return 0;
-}
-
 /**
  * drm_fb_helper_remove_conflicting_framebuffers - remove firmware-configured framebuffers
  * @a: memory range, users of which are to be removed