drm/i915/xelpdp: Add XE_LPDP_FEATURES

Add a FEATURES macro for XE_LPD+ as this is expected to be the baseline
for Xe2_LPD and will allow to see the delta more easily.

v2: Move everything from xe_lpdp_display to the new macro and remove
    the version setting: it's not needed with GMD_ID.

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/20230919192128.2045154-1-lucas.demarchi@intel.com