Allwinner V3s come with a USB PHY controller slightly different to other
SoCs, with only one PHY.

Add support for it.
Signed-off-by: NIcenowy Zheng <icenowy@aosc.xyz>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>