arm64: dts: mt8167: Align mmsys node name with dtschema

The node name should be generic and mmsys expcets 'syscon'

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230209160357.19307-2-matthias.bgg@kernel.org


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