dts: qcs404-evb: Add USB controller and PHY nodes

QCS404 SoC provides support for two USB controllers: one USB3 and the
other one being USB2. The USB3 controller supports further 2 PHY: one high
speed PHY and the other super speed PHY. The USB2 controller supports a
single high speed PHY. So add corresponding DT nodes.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>