drm/todo: Update drm_fb_helper tasks

drm_fb_helper tasks are completed now hence remove them from
todo list.

Changes since v1:
* remove entire drm_fb_helper tasks from todo list. Daniel's
  "64914da2 drm/fbdev-helper: don't force restores" already fixes
  first one (Daniel)
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>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305120434.111091-8-pankaj.laxminarayan.bharadiya@intel.com

Documentation/gpu/todo.rst

@@ -359,23 +359,6 @@ Contact: Sean Paul
 
 Level: Starter
 
-drm_fb_helper tasks
--------------------
-
-- drm_fb_helper_restore_fbdev_mode_unlocked() should call restore_fbdev_mode()
-  not the _force variant so it can bail out if there is a master. But first
-  these igt tests need to be fixed: kms_fbcon_fbt@psr and
-  kms_fbcon_fbt@psr-suspend.
-
-- The max connector argument for drm_fb_helper_init() isn't used anymore and
-  can be removed.
-
-- The helper doesn't keep an array of connectors anymore so these can be
-  removed: drm_fb_helper_single_add_all_connectors(),
-  drm_fb_helper_add_one_connector() and drm_fb_helper_remove_one_connector().
-
-Level: Intermediate
-
 connector register/unregister fixes
 -----------------------------------