UPSTREAM: kbuild: clang: Disable 'address-of-packed-member' warning

clang generates plenty of these warnings in different parts of the code,
to an extent that the warnings are little more than noise. Disable the
'address-of-packed-member' warning.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit bfb38988c51e440fd7062ddf3157f7d8b1dd5d70)
Signed-off-by: Greg Hackmann <ghackmann@google.com>

Change-Id: I35ecf1b35a908d41ee791a8a651e3cfb4edd081b