Staging: dgnc: dgnc_driver.h: remove unnecessary comments

The public headers is well known by others and the redundant commits make
the code mess. Remove the comments of the public headers to make the code
tidy.

Signed-off-by: Navy Cheng <navych@126.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>