The numbers associated to each port mode given by the AT^GETPORTMODE response are not USB interface numbers, they are 'port numbers'. Moreover, these numbers may start either at 0 or at 1, depending on the firmware. The only reasonable way to parse this response is to just gather the order of all the port modes reported, and apply the modes to each serial port found in the system in the same order. Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/239