drm/i915: use DISPLAY_VER() instead of accessing match_info directly

We've just set up device info in i915_driver_create() so we can use
DISPLAY_VER() intead of looking at match_info directly.

Semantically we want to check the display version instead of the
graphics version, and for the earlier platforms they are always the
same.

v2: Use DISPLAY_VER() instead of GRAPHICS_VER() (Ville)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220628141005.226252-1-jani.nikula@intel.com