arm64: dts: mediatek: mt8188: Fix IOMMU device for rdma0

arm64: dts: mediatek: mt8188: Fix IOMMU device for rdma0

Based on the comments in the MT8188 IOMMU binding header, the rdma0
device specifies the wrong IOMMU device for the IOMMU port it is
tied to:

    This SoC have two MM IOMMU HWs, this is the connected information:
    iommu-vdo: larb0/2/5/9/10/11A/11C/13/16B/17B/19/21
    iommu-vpp: larb1/3/4/6/7/11B/12/14/15/16A/17A/23/27

rdma0's endpoint is M4U_PORT_L1_DISP_RDMA0 (on larb1), which should use
iommu-vpp, but it is currently tied to iommu-vdo.

Somehow this went undetected until recently in Linux v6.15-rc1 with some
IOMMU subsystem framework changes that caused the IOMMU to no longer
work. The IOMMU would fail to probe if any devices associated with it
could not be successfully attached. Prior to these changes, only the
end device would be left without an IOMMU attached.

Fixes: 7075b21d1a8e ("arm64: dts: mediatek: mt8188: Add display nodes for vdosys0")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250408092303.3563231-1-wenst@chromium.org
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>