drm/todo: Update panic handling todo

Some things changed, and add two useful links.

v2: Also include a link to the QR encoding work. Plus review from
Javier.

v3: Fix typo Guilherme spotted.

Reviewed-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Cc: gpiccoli@igalia.com
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220224132425.3463791-1-daniel.vetter@ffwll.ch