Staging: comedi: set PCI and PCMCIA defines

The comedi drivers are looking for CONFIG_COMEDI_PCI and
CONFIG_COMEDI_PCMCIA, not the current config items.  This creates a
define so that things build properly when these options are selected.
Long term goal is to fix up the drivers to not need any defines.

Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>