staging: comedi: ni_pcidio: remove DEBUG define

This define is only used to enable some debug messages during the
board attach. These are just added noise, remove them as well as
the DEBUG 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>