winsys/amdgpu: use the no-op helper to detect if reset completion

winsys/amdgpu: use the no-op helper to detect if reset completion

On older kernel the completion of the reset isn't signalled to userspace,
yet we need it to implement the EXT_robustness extension correctly.

In this situation, try to create a new context and submit a no-op job. If
the reset isn't done the kernel will reject the submission (-ECANCELED);
otherwise the submission will go through and we'll know that the reset is
done.

Reviewed-by: André Almeida <andrealmeid@igalia.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22290>