panfrost: Remove old comment on broken depth reload

Depth reload works now, so now the optimisation is just for
performance and isn't a workaround any more.

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6609>
1 file changed