dt-bindings: devfreq: samsung,exynos-ppmu: Use standard regex syntax

The "{,N}" regex syntax is non-standard, but happens to be supported by
python re module. It is equivalent to "{0,N}" which is more commonly
supported. This fixes using a rust implementation of the DT schema
tools.

Link: https://patch.msgid.link/20260813174037.2263884-1-robh@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Documentation/devicetree/bindings/devfreq/event/samsung,exynos-ppmu.yaml

@@ -40,7 +40,7 @@ properties:
     type: object
 
     patternProperties:
-      '^ppmu-event[0-9]+(-[a-z0-9]+){,2}$':
+      '^ppmu-event[0-9]+(-[a-z0-9]+){0,2}$':
         type: object
         properties:
           event-name: