staging: comedi: adl_pci9118: always try to use interrupt and DMA

This driver currently supports both the (*auto_attach) and legacy (*attach)
mechanisms. The (*auto_attach) always tries to use the interrupt and DMA to
support async commands with the analog input subdevice. The legacy (*attach)
only enables them depending on a user option that is passed to the (*attach).
The 'default' (i.e. option == 0) is to enable both the interrupt and DMA.

Simplify the attach by always trying to enable the interrupt and DMA.

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