staging: comedi: das1800: remove 'resolution' boardinfo

The "hr" type boards have 16-bit analog inputs and outputs.
All other board types have 12-bit.

Remove the 'resolution' member of the boardinfo and use the
'id' member to determine the subdevices 'maxdata'.

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>