iris/gen11+: Calculate pixel hashing tables instead of hardcoding.

iris/gen11+: Calculate pixel hashing tables instead of hardcoding.

Pixel hashing tables are a pain to type in, review and maintain IMHO.
In order to obtain satisfactory load balancing on all Gen12 parts
currently in production this series would need to add 5 different
additional tables.  Instead this introduces a simple algorithm able to
calculate a table on the fly based on a handful of parameters.

Note that the Gen11 tables generated with this algorithm are not
identical to the hardcoded ones, however the only difference should be
a phase shift that isn't expected to have any effect on performance,
since it shouldn't change the fraction of work submitted to each pixel
pipe.

The CPU overhead from this change is negligible since the tables only
need to be programmed once at context init time.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8749>