usb: cdc-wdm: Add device-id for Huawei 3G/LTE modems

[v2: Editorial changes suggested by Sergei Shtylyov]

These modems use the Qualcomm MSM Interface (QMI) protocol for
management of their CDC ECM like wwan interface.  This driver
is perfect for exporting the protocol to userspace.

The created character device will be indistinguishable from a
common AT command based Device Management interface, so
userspace applications must do some intelligent matching
on the USB device.

Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>