staging: comedi: das08: Remove manual configuration of PCI boards

Remove the code that allows PCI boards to be manually attached by the
`COMEDI_DEVCONFIG` ioctl (or the `comedi_config` application).
Supported PCI boards will be attached automatically at probe time via
`comedi_pci_auto_config()` and the `attach_pci` hook in the `struct
comedi_driver`.

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