appletalk: move to staging

For all I know, Appletalk is dead, the only reasonable
use right now would be nostalgia, and that can be served
well enough by old kernels. The code is largely not
in a bad shape, but it still uses the big kernel lock,
and nobody seems motivated to change that.

FWIW, the last release of MacOS that supported Appletalk
was MacOS X 10.5, made in 2007, and it has been abandoned
by Apple with 10.6. Using TCP/IP instead of Appletalk has
been supported since MacOS 7.6, which was released in
1997 and is able to run on most of the legacy hardware.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>