staging: comedi: cb_pcidda: refactor iobase addresses

This driver uses two iobase addresses, found in PCI bars 2 and 3.
Currently, the address in PCI bar 3 is saved in the comedi_device as
the 'iobase' and the one in PCI bar 2 is just passed to subdev_8255_init()
as the 'iobase' parameter.

Save the PCI bar 3 address in the private data as 'daqio' and the
address from PCI bar 2 in the comedi_device as the 'iobase'.

This will help with some cleanup of the 8255 module.

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>