We define 3 common udev tag ids to be used by all plugins:
* ID_MM_PORT_TYPE_AT_PRIMARY: the primary modem port. It will be used
for AT control and also as PPP if there is no other port flagged
explicitly to do PPP.
* ID_MM_PORT_TYPE_AT_SECONDARY: the secondary modem port. It will be
used when/if the primary port gets connected to do PPP.
* ID_MM_PORT_TYPE_PPP: the port to be used to do PPP only. This tag
makes sense only when the primary port shouldn't be used for PPP,
i.e. when there is a port dedicated to do PPP and one port
dedicated for control.
Aleksander Morgado
6b0424cfac