drm/i915/display: convert display device identification to struct intel_display

drm/i915/display: convert display device identification to struct intel_display

Convert intel_display_device.[ch] to struct intel_display, including
callers, but excluding intel_display_device_probe() which will be
handled in follow-up.

v2: fix display->drm = display->drm goof-up

Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/865b27b66f599e707081d46fca9f679e19a4e8aa.1731321183.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>