meta-schemas: Ensure json-schema vocab aren't DT property names

It's very easy to define json-schema vocabulary as DT properties by
mistake if the indentation is wrong.

There's unlikely to be much overlap. 'type' is one such case though.

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

meta-schemas/core.yaml

@@ -30,6 +30,15 @@ definitions:
         $ref: "string-array.yaml"
       memory-region:
         $ref: "cell.yaml#array"
+    propertyNames:
+      # Ensure DT property names are not json-schema vocabulary names
+      not:
+        enum: [ $ref, additionalItems, additionalProperties, allOf, anyOf,
+                const, contains, default, dependencies, deprecated, description,
+                else, enum, if, items, maxItems, maximum, minItems, minimum,
+                multipleOf, not, oneOf, pattern, patternProperties, properties,
+                propertyNames, required, then, unevaluatedProperties ]
+
     patternProperties:
       '.*-names$':
         $ref: "string-array.yaml"