staging: dgnc: remove dead code

Driver contains dead code, guarded with #ifdef's. We can safely remove
this, it will be in the git history if it is later needed.

Remove dead code.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>