arm64: dts: mt6779: Support devapc

Support DEVAPC on MT6779 platforms by adding device node.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
Reviewed-by: Hanks Chen <hanks.chen@mediatek.com>
Link: https://lore.kernel.org/r/1608713092-26952-2-git-send-email-neal.liu@mediatek.com


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