usb: serial: Add Rigblaster Advantage to device table

The Rigblaster Advantage is an amateur radio interface sold by West Mountain
Radio. It contains a cp210x serial interface but the device ID is not in
the driver.

Signed-off-by: Steve Conklin <sconklin@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>