arm64: dts: marvell: armada-37xx: link USB hosts with their PHYs

Reference the PHY nodes from the USB controller nodes.

The USB3 host controller is wired to:
  * the first PHY of the COMPHY IP
  * the OTG-capable UTMI PHY

The USB2 host controller is wired to:
  * the host-only UTMI PHY

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>