ARM: dts: armada-385-linksys: usb3 label cleanup

Now that we use the reference for the USB3.0 port update the node name
and labels for the phy and vbus to match the label used by
armada-38x.dtsi.

Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>