staging: comedi: pass struct comedi_driver * to comedi_auto_config()

Pass a pointer to the struct comedi_driver to comedi_auto_config()
instead of the driver name.  comedi_auto_config() will be changed to
make use of this.  It currently calls comedi_device_attach() which
examines the whole list of struct comedi_driver objects.  It will be
changed to restrict itself to just the supplied struct comedi_driver
object.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>