dt-bindings: mediatek: mmsys: add mt8167 binding

Add binding documentation for MT8167 SoC.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210405200354.2194930-1-fparent@baylibre.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>