staging: comedi: pcl816: all board types have digital inputs and outputs

All the board types have 16 digital inputs and 16 digital outputs.

Remove the 'n_dichan' and 'n_dochan' members in the boardinfo.

The subdevice support code is currently incomplete in this driver. For
now just tidy up the incomplete subdevice code in pcl816_attach().

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>