staging: comedi: ni_6527: change MODULE_DESCRIPTION

Change the MODULE_DESCRIPTION to something useful instead of the
generic "Comedi low-level driver".

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>