ARM64: dts: meson-gxl-s905x-libretech-cc: enable the USB controller

The LibreTech CC ("Le Potato") board provides four USB connectors.
These are provided by a hub which is connected to the SoC's USB
controller.
Enable the SoC's USB controller to make the USB ports usable. Also turn
on the HDMI_5V regulator when powering on the PHY because (even though
it's not shown in the schematics) HDMI_5V also supplies the USB VBUS.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>