telit: Detect 4G BND format from BND test reply
Telit modems that require hexadecimal number when specifying 4G bands also reply to #BND=? command with a 4th parameter <LTE_band_ext> (e.g. LM940, LM960, LN920, FN980). On the other hand, modems that require decimal number when specifying 4G bands only return 3 parameters to the same command.
It is then possible replace the detection of ext_4g_bands via UDEV tags with an inspection of BND=? reply.
Edited by Aleksander Morgado