drm/xe/rps: build RPS as part of xe
Reduce the conditional compilation in i915 by building
intel_display_rps.c as part of the xe module. This doesn't actually
enable RPS on xe, because there's no parent interface implementation on
xe side, but it's a step in the right direction.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/93df0bb727fce14aa9a542dbd2c0826a0fa0a16f.1763370931.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>