arm64: dts: rockchip: rk3588s-rock5a: add USB3 host

Enable USB3 host controller for the Radxa ROCK 5 Model A. This adds
USB3 for the lower USB3 port (the one closer to the PCB).

The upper USB3 port uses the RK3588 USB TypeC host controller, which
uses a different PHY that is not yet supported upstream.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

arch/arm64/boot/dts/rockchip/rk3588s-rock-5a.dts

@@ -114,6 +114,10 @@
 	};
 };
 
+&combphy2_psu {
+	status = "okay";
+};
+
 &cpu_b0 {
 	cpu-supply = <&vdd_cpu_big0_s0>;
 };
@@ -734,3 +738,7 @@
 &usb_host1_ohci {
 	status = "okay";
 };
+
+&usb_host2_xhci {
+	status = "okay";
+};