iris: Let isl decide the supported tiling in more situations

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Suggested-by: Nanley Chery <nanley.g.chery@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
49 jobs for !2048 with gen12-isl in 20 minutes and 34 seconds (queued for 9 seconds)
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