staging: comedi: rtd520: remove unnecessary function desc. block comments

These function description comments are cut-and-paste cruft from the
old skeleton driver. Remove them.

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>