commit 878c69aa upstream.

Some (very few) early devices like mine, where not exposting a proper CDC
descriptor. This was fixed with an immediate firmware update from the vendor,
and pre-installed on newer devices.
So actual devices can be driven by cdc_acm.c + cdc_ether.c.
Signed-off-by: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>