drm/i915: nuke the intel_lvds_connector

For a while we carried lvds connector specific data in the lvds
connector, but since commit 05c72e77

 ("drm/i915: Nuke the LVDS lid
notifier") we haven't needed it. Revert back to plain intel_connector.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181009210916.19578-1-jani.nikula@intel.com