Basic ublox TOBY-L4 support

[Aleksander Morgado]

Hey,

The following patches introduce support for using the u-blox TOBY-L4 modem with ModemManager. For the looks of it, it can be considered a 'subset' of the TOBY-L2, with one single USB profile (NCM based) and one single networking mode (Router mode).

Comments?

    [PATCH 1/4] ublox: allow creating u-blox bearers if...
    [PATCH 2/4] ublox: fallback to router mode if networking mode unknown
    [PATCH 3/4] ublox: if authentication not required, ignore +UAUTHREQ=0
    [PATCH 4/4] ublox: define port type hints for the TOBY-L4