USB: support for cdc-acm of single interface devices

This implement support in cdc-acm for acm devices another popular OS can handle

- adds support for autodetection of devices that use one interface
- autodetection of endpoints
- add a quirk for surpressing a setting that OS doesn't use
- autoassume that quirk for single interface devices

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>