docs/ja_JP/SubmittingPatches: Add Suggested-by as a standard signature

docs/ja_JP/SubmittingPatches: Add Suggested-by as a standard signature

Reflect changes made in commit b1a429ae37d9 ("checkpatch: add
Suggested-by as a standard signature").

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Tsugikazu Shibata <shibata@linuxfoundation.org>
Cc: Kosuke Fujimoto <fujimotokosuke0@gmail.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Tsugikazu Shibata <shibata@linuxfoundation.org>
Reviewed-by: Kosuke Fujimoto <fujimotokosuke0@gmail.com>
Link: https://lore.kernel.org/r/20220503104757.49208-1-akiyks@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>