Adding support "PSC Scanning, Magellan 800i" in cdc-acm

Very simple, but very necessary.
Suitable for all versions of the kernel > 2.6
Signed-off-by: Denis N Ladin <denladin@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>