Don't access i915->vbt.ddi_port_info[] directly.
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/9e4fcb625cec26ee88245aad7ae80bfe93b14e59.1579270868.git.jani.nikula@intel.com