drm/i915/bmg: BMG should re-use MTL's south display logic

drm/i915/bmg: BMG should re-use MTL's south display logic

Battlemage's south display is the same as Meteor Lake's, including the
need to invert the HPD pins, which Lunar Lake does not need.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Reviewed-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240430172850.1881525-14-radhakrishna.sripada@intel.com