staging: comedi: cb_pcimdda: use attach_pci callback

Convert this PCI driver to use the comedi PCI auto config attach
mechanism by adding an 'attach_pci' callback function.

This driver does use an external configuration option to determine
the analog output range which is controlled by a jumper on the board.
In order to remove the legacy 'attach' callback, an assumption is made
that the jumper is in the factory setting position for +/-5V outputs.
This does not effect the operation of the board just the range info
that is returned to the user.

A sysfs method will be investigated to allow the user to change the
range.

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>