drm/xe/display: move compat uncore stubs to the correct file

Move things that belong to intel_uncore.h to the correct place.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3f3903c7c5e34aefac0f6d06e433710bc782c97e.1717004739.git.jani.nikula@intel.com