ARM: dts: sun9i: Add usb phy nodes to a80 dtsi

On sun9i, there are 3 independent usb phys for EHCI/OHCI.
Add device nodes for them.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>