ARM: dts: sun8i: add a cpu0 label to cpu@0 node on A23/33

A "cpu0" label is needed on cpu@0 for cpufreq-dt to work.

Add such a label, in order to prepare for cpufreq support of A23/33.
Signed-off-by: NIcenowy Zheng <icenowy@aosc.xyz>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-a23-a33.dtsi

@@ -84,7 +84,7 @@
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-		cpu@0 {
+		cpu0: cpu@0 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
 			reg = <0>;