Define a common set of Xe2 graphics feature flags and definitions that
will be used for all platforms in this family.

Several of the feature flags are inherited unchanged from Xe_HP and/or
Xe_HPC platforms:
 - dma_mask_size remains 46   (Bspec 70817)
 - supports_usm=1             (Bspec 59651)
 - has_flatccs=1              (Bspec 58797)
 - has_asid=1                 (Bspec 59654, 59265, 60288)
 - has_range_tlb_invalidate=1 (Bspec 71126)

However some of them still need proper implementation in the driver to
be used, so they are disabled.

Notable Xe2-specific changes:
 - All Xe2 platforms use a five-level page table, regardless of the
   virtual address space for the platform.  (Bspec 59505)

The graphics engine mask represents the Xe2 architecture engines (Bspec
60149), but individual platforms may have a reduced set of usable
engines, as reflected by their fusing.

Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>