staging: comedi: adv_pci_dio: rename PCI1752_6_CFC define

For aesthetics, rename this define and fix the alignment.

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>