USB: serial: ftdi: add CONTEC vendor and product id

This is a patch to ftdi_sio_ids.h and ftdi_sio.c that adds
identifiers for CONTEC USB serial converter. I tested it
with the device COM-1(USB)H

Signed-off-by: Daniel Sangorrin <daniel.sangorrin@gmail.com>
Cc: Andreas Mohr <andi@lisas.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>