uqmi: configure PDP type and APN to modem

uqmi: configure PDP type and APN to modem

Configure the PLMN and APN to the modem. This is required in cases,
where either the SGSN or GGSN does not permit the selection of IPv4v6
pdp type.

Previously, the modem always tried to establish a dual-stacked PDP
context regardless of the configured PDP type in uci. As this setting
can not be parameterized when creating a WDS context, configure it to
the modems internal list of profiles. This way, the PDP type is taken
into account when creating the WDS context.

Signed-off-by: David Bauer <mail@david-bauer.net>