arm64: dts: mediatek: mt8516: add usb1 node

The MT8516 has 2 USB instances. Add support for the second USB instance.
usb1 can only work in host mode.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Link: https://lore.kernel.org/r/20201014162404.1312544-2-fparent@baylibre.com


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