drm/i915: Add XE_HP initial definitions

Our _FEATURES macro went back to GEN7, extending each other, making it
difficult to grasp what was really enabled/disabled. Take the
opportunity of the GEN -> XE_HP name break and also break with the
feature inheritance.

For XE_HP this basically goes from GEN12 back to GEN7 coalescing the
features making sure the overrides remain, remove all the
display-specific features and sort it.

Then also remove the definitions that would be overridden by
DGFX_FEATURES and those that were 0 (since that is the default).
Exception here is has_master_unit_irq: although it is a feature that
started with DG1 and is true for all DGFX platforms, it's also true for
XE_HP in general.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721223043.834562-2-matthew.d.roper@intel.com