ARM64: dts: meson-gxbb-nexbox-a95x: Enable USB Nodes

Enable both gxbb USB controllers and add a 5V regulator for the OTG port
VBUS, similar to p20x.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>