anv: restrict number of subgroups per group

We are limited to 64 threads per dispatched group, regardless of what
num_cs_threads claims, so advertise that limit correctly.

Fixes (on TGL and up):
dEQP-VK.subgroups.size_control.compute.required_subgroup_size_min
and other *.required_subgroup_size_min tests.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7453>
1 file changed