staging: comedi: ni_daq_dio24: convert to auto attach

Convert this pcmcia driver to the comedi auto attach mechanism.

This allows getting rid of the "hack" needed to pass the pcmcia_device
pointer from the pcmcia_driver to the comedi_driver as well as the
now unnecessary boardinfo.

Check the call to subdev_8255_init() for success. That function does
a kzalloc and could return -ENOMEM.

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>