staging: comedi: cb_pcidio: store the iobase in the comedi_device

Save the pci bar in dev->iobase instead of carrying it in the
private data.

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>