dt-bindings: mediatek: mt8186: Add binding for MM iommu

Add mt8186 iommu binding. "-mm" means the iommu is for Multimedia.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220503071427.2285-4-yong.wu@mediatek.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>