qmi_wwan: Added support for Cinterion's PLxx WWAN Interface

Added support for Cinterion's PLxx WWAN Interface by adding QMI_FIXED_INTF with
Cinterion's Vendor ID as well as Product ID and WWAN Interface Number.

Signed-off-by: Hans-Christoph Schemmel <hans-christoph.schemmel@gemalto.com>
Signed-off-by: Christian Schmiedl <christian.schmiedl@gemalto.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>