drm/i915: Extract intel_lvds_add_properties()

Move the LVDS connector property setup to a dedicated
function to depollute intel_lvds_init() a bit.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220912111814.17466-10-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>