cdc_ncm: Flag Intel OEM version of Fibocom L850-GL as WWAN

This lets NetworkManager/ModemManager know that this is a modem and
needs to be connected first.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Link: https://patch.msgid.link/20250814154214.250103-1-lkundrak@v3.sk


Signed-off-by: Jakub Kicinski <kuba@kernel.org>