drm: drop drm_bus from todo

David Herrmann removed the last bits of drm_bus in:
commit c5786fe5f1 ("drm: Goody bye, drm_bus!")

Remove the todo item.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com> [I miss drm_bus!]
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20190126192732.15263-1-sam@ravnborg.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190126192732.15263-1-sam@ravnborg.org

Documentation/gpu/todo.rst

@@ -10,25 +10,6 @@ graphics subsystem useful as newbie projects. Or for slow rainy days.
 Subsystem-wide refactorings
 ===========================
 
-De-midlayer drivers
--------------------
-
-With the recent ``drm_bus`` cleanup patches for 3.17 it is no longer required
-to have a ``drm_bus`` structure set up. Drivers can directly set up the
-``drm_device`` structure instead of relying on bus methods in ``drm_usb.c``
-and ``drm_pci.c``. The goal is to get rid of the driver's ``->load`` /
-``->unload`` callbacks and open-code the load/unload sequence properly, using
-the new two-stage ``drm_device`` setup/teardown.
-
-Once all existing drivers are converted we can also remove those bus support
-files for USB and platform devices.
-
-All you need is a GPU for a non-converted driver (currently almost all of
-them, but also all the virtual ones used by KVM, so everyone qualifies).
-
-Contact: Daniel Vetter, Thierry Reding, respective driver maintainers
-
-
 Remove custom dumb_map_offset implementations
 ---------------------------------------------