staging: comedi: ni_tio: tidy up Gi_Reset_Bit

Convert this inline CamelCase function into a define.

For aesthetics, move the new define so it is associated with the
register define.

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>