staging: comedi: das08: split out bus specific code

Split the bus specific ISA/PC-104 and PCI code out of this driver
and create two new drivers, das08_isa and das08_pci.

This allows removing all the #ifdef'ery in the das08 driver that
handled if the CONFIG_COMEDI_DAS08_{ISA,PCI} options were enabled.

It also makes the PCI driver cleanly Plug-and-Play since the comedi
driver only has an auto_attach callback. Previously it also had an
attach callback in order to handle the ISA cards.

Since the PCMCIA support was already split out, we can also remove
the now unused enum das08_bustype and it's use in the boardinfo.
The bus specific code deals with the bustype automatically before
it calls the common attach function in das08.

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>