docs/zh_CN: add dt overlay-notes translation

Translate .../devicetree/overlay-notes.rst into Chinese.

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/b957580e448e2d0ab7917644c8f8f1614060b20a.1662449105.git.siyanteng@loongson.cn


Signed-off-by: Jonathan Corbet <corbet@lwn.net>