staging: comedi: pcl730: add support for the P8R8-DIO ISA board

The ICP P8R8-DIO ISA boards can be supported by this driver. This board
has 8 isolated digital outputs and 8 isolated digital outputs.

Add support for this board to the pcl730 driver.

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