staging: comedi: dyna_pci10xx: use dev->iobase

Use dev->iobase to hold one of the pci base addresses used
by the driver 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>