evpriv->iobase

Currently, devpriv->iobase is used to hold the PCI bar 2 base address
used to read/write the registers on the board. The same information
is stored in the comedi_device dev->iobase. Use that instead.

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