intel/aux_map: Ignore format bits when using tile-4

intel/aux_map: Ignore format bits when using tile-4

Based on Jianxun's ("iris: don't get format bits in AUX tables").

With gfx12.5+, the compression format is once again coming from the
surface state programming. MTL once again uses an aux-map, but it
ignores the format bits within the the aux-map metadata.

Ref: Bspec 44930: "Compression format from AUX page walk is ignored.
Instead compression format from Surface State is used."

gfx12.5+ also uses tile-4 rather than y-tiling, so if we don't see
y-tiling, we can return 0 from intel_aux_map_format_bits() for the
ignored format bits.

Rework:
 * Just return 0 if not using y-tiling as suggested by Nanley.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
Reviewed-by: Jianxun Zhang <jianxun.zhang@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20322>