dt-bindings: power: renesas,apmu: Group tuples in cpus properties

To improve human readability and enable automatic validation, the tuples
in "cpus" properties in device nodes for Advanced Power Management Units
for AP-System Core (APMU) should be grouped using angle brackets.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210204125542.1645925-1-geert+renesas@glider.beSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/power/renesas,apmu.yaml

@@ -52,5 +52,5 @@ examples:
     apmu@e6152000 {
             compatible = "renesas,r8a7791-apmu", "renesas,apmu";
             reg = <0xe6152000 0x188>;
-            cpus = <&cpu0 &cpu1>;
+            cpus = <&cpu0>, <&cpu1>;
     };