drm/i915/lnl: Add display definitions

Add Lunar Lake platform definitions for i915 display. The support for
LNL will be added to the xe driver, with i915 only driving the display
side. Xe2 display is derived from the Xe_LPD+ IP; additional feature
deltas will be introduced in subsequent patches, so here it's just
adding a separate xe2_lpd_display struct.

v2: Use a LPDP_FEATURES macro (Matt Roper)

Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919192128.2045154-2-lucas.demarchi@intel.com