drm/todo: Convert list of fbconv links to footnotes

Convert the references to fbconv links to footnotes, so they can be
navigated.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/0761f98d3b6f8df9eea977eae063e35b450fda9e.1689779916.git.geert+renesas@glider.be

Documentation/gpu/todo.rst

@@ -757,16 +757,16 @@ existing hardware. The new driver's call-back functions are filled from
 existing fbdev code.
 
 More complex fbdev drivers can be refactored step-by-step into a DRM
-driver with the help of the DRM fbconv helpers. [1] These helpers provide
+driver with the help of the DRM fbconv helpers [4]_. These helpers provide
 the transition layer between the DRM core infrastructure and the fbdev
 driver interface. Create a new DRM driver on top of the fbconv helpers,
 copy over the fbdev driver, and hook it up to the DRM code. Examples for
-several fbdev drivers are available at [1] and a tutorial of this process
-available at [2]. The result is a primitive DRM driver that can run X11
-and Weston.
+several fbdev drivers are available in Thomas Zimmermann's fbconv tree
+[4]_, as well as a tutorial of this process [5]_. The result is a primitive
+DRM driver that can run X11 and Weston.
 
- - [1] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv
- - [2] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c
+ .. [4] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv
+ .. [5] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c
 
 Contact: Thomas Zimmermann <tzimmermann@suse.de>