dt-bindings: arm/cpus: Allow 2 power-domains entries

Some platforms have both "perf" and "psci" power domains, so allow 2
entries.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: robherring

Documentation/devicetree/bindings/arm/cpus.yaml

@@ -313,15 +313,19 @@ properties:
     maxItems: 1
 
   power-domains:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   power-domain-names:
     description:
       For PSCI based platforms, the name corresponding to the index of the PSCI
       PM domain provider, must be "psci". For SCMI based platforms, the name
       corresponding to the index of an SCMI performance domain provider, must be
       "perf".
-    enum: [ psci, perf, cpr ]
+    minItems: 1
+    maxItems: 2
+    items:
+      enum: [ psci, perf, cpr ]
 
   resets:
     maxItems: 1