Because the decoder nodes already make use of the iommus property to
configure the IOMMU for address translations, having a dma-ranges
property makes no sense.

In fact, after commit f1ad5338 ("of: Fix "dma-ranges" handling for
bus controllers"), having a dma-ranges property causes IOMMU faults.

Remove the dma-ranges property and update the example.
Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>