arm64: dts: renesas: beacon: Fix USB ref clock references

The RZ/G2 boards expect there to be an external clock reference for
USB2 EHCI controllers. For the Beacon boards, this reference clock
is controlled by a programmable versaclock. Because the RZ/G2
family has a special clock driver when using an external clock,
the third clock reference in the EHCI node needs to point to this
special clock, called usb2_clksel.

Since the usb2_clksel does not keep the usb_extal clock enabled,
the 4th clock entry for the EHCI nodes needs to reference it to
keep the clock running and make USB functional.

Signed-off-by: Adam Ford <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Geert Uytterhoeven <[e-mail]>

arch/arm64/boot/dts/renesas/beacon-renesom-baseboard.dtsi

···
 &ehci0 {
 	dr_mode = "otg";
 	status = "okay";
-	clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>;
+	clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>, <&usb2_clksel>, <&versaclock5 3>;
 };
 
 &ehci1 {
 	status = "okay";
-	clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>;
+	clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>, <&usb2_clksel>, <&versaclock5 3>;
 };
 
 &hdmi0 {