usb: serial: mos7840: Add USB IDs to support more B&B USB/RS485 converters.

Add the USB IDs needed to support the B&B USOPTL4-4P, USO9ML2-2P, and
USO9ML2-4P.  This patch expands and corrects a typo in the patch sent
on 08-31-2010.

Signed-off-by: Dave Ludlow <dave.ludlow@bay.ws>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>