serial: add support for OX16PCI958 card

Signed-off-by: Lytochkin Boris <lytboris@gmail.com>
Tested-by: Lytochkin Boris <lytboris@gmail.com>
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>