staging: comedi: cb_pcimdas: provide analog output range table

The analog output range is not programmable. The DAC ranges are
jumper-settable on the board. For aesthetics, provide a range table
for the user with all possible ranges.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>