staging: comedi: daqboard2000: remove unused 'card' member

The `card` member of `struct daqboard2000_private` and the enumerated
constant `card_daqboard_2000` are not used.  Remove them.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/daqboard2000.c

@@ -256,9 +256,6 @@ static const struct daq200_boardtype boardtypes[] = {
 };
 
 struct daqboard2000_private {
-	enum {
-		card_daqboard_2000
-	} card;
 	void __iomem *plx;
 };