arm64: dts: mt8183: add scp node

Add scp node to mt8183 and mt8183-evb

Signed-off-by: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Link: https://lore.kernel.org/r/20191112110330.179649-5-pihsun@chromium.org
Link: https://lore.kernel.org/r/20200909081422.2412795-1-pihsun@chromium.org


[mb: squashed both patches]
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>