arm64: dts: rockchip: enable usb hub on the radxa rock3 model a

One USB 2.0 host port on the Radxa ROCK3 Model A is connected to the
SoC via a hub. Introduce a voltage regulator to enable this USB hub.

Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220425133502.405512-3-michael.riesch@wolfvision.net


Signed-off-by: Heiko Stuebner <heiko@sntech.de>