drm/i915/display: keep struct intel_display members sorted

Like the comment says,

	/* Grouping using anonymous structs. Keep sorted. */

Stick to it.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231114155528.96935-1-jani.nikula@intel.com