arm64: dts: mediatek: mt8195: revise VDOSYS RDMA node name

DMA-related nodes have their own standardized naming. Therefore,
the MT8195 VDOSYS RDMA has been unified and corrected.
Additionally, these modifications will facilitate the further
integration of bindings.

Fixes: 92d2c23d ("arm64: dts: mt8195: add display node for vdosys1")
Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>