drm/xe/display: remove the unused compat HAS_GMD_ID()

The display code no longer needs or uses HAS_GMD_ID(). Remove it from
the compat header.

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/67571bb0b10fb5c99dba57757f2213ef39bdedbb.1724180287.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>