net: usb: cdc_ether: add support for Thales Cinterion PLS62-W modem

net: usb: cdc_ether: add support for Thales Cinterion PLS62-W modem

This modem has 7 interfaces, 5 of them are serial interfaces and are
driven by cdc_acm, while 2 of them are wwan interfaces and are driven
by cdc_ether:
If 0: Abstract (modem)
If 1: Abstract (modem)
If 2: Abstract (modem)
If 3: Abstract (modem)
If 4: Abstract (modem)
If 5: Ethernet Networking
If 6: Ethernet Networking

Without this change, the 2 network interfaces will be named to usb0
and usb1, our QA think the names are confusing and filed a bug on it.

After applying this change, the name will be wwan0 and wwan1, and
they could work well with modem manager.

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230105034249.10433-1-hui.wang@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>