staging: comedi: daqboard2000: rename CamelCase functions

Rename functions to avoid CamelCase warnings from checkpatch, and to use
namespace associated with the driver.

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>