comedi: Uncripple 8255-based DIO subdevices

comedi: Uncripple 8255-based DIO subdevices

(Note: upstream comedi configuration has been overhauled, so this patch
does not apply there.)

Several comedi drivers call subdev_8255_init() (declared in
"drivers/staging/comedi/drivers/8255.h") to set up one or more DIO
subdevices.  This should be provided by the 8255.ko module, but unless
the CONFIG_COMEDI_8255 or CONFIG_COMEDI_8255_MODULE macro is defined,
the 8255.h header uses a dummy inline version of the function instead.
This means the comedi devices end up with an "unused" subdevice with 0
channels instead of a "DIO" subdevice with 24 channels!

This patch provides a non-interactive COMEDI_8255 option and selects it
whenever the COMEDI_PCI_DRIVERS or COMEDI_PCMCIA_DRIVERS options are
selected.

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