panfrost: Copy resources when mapping to avoid waiting for readers

It is often faster to copy the whole resource and modify that than
to flush and wait for readers of the BO.

Helps anything which updates textures after already using them in a
frame, such as most GLQuake ports.

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5573>
1 file changed