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