dt-bindings: memory-controllers: Make "additionalProperties: true" explicit

Make it explicit that child nodes have additional properties and the
child node schema is not complete. The complete schemas are applied
separately based the compatible strings.

Signed-off-by: Rob Herring <[e-mail]>
Reviewed-by: Roger Quadros <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Krzysztof Kozlowski <[e-mail]>

Documentation/devicetree/bindings/memory-controllers/ingenic,nemc.yaml

···
   ".*@[0-9]+$":
     type: object
     $ref: mc-peripheral-props.yaml#
+    additionalProperties: true
 
 required:
   - compatible

Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.yaml

···
 patternProperties:
   "flash@[0-9a-f]+$":
     type: object
+    additionalProperties: true
+
     properties:
       compatible:
         contains:

Documentation/devicetree/bindings/memory-controllers/ti,gpmc.yaml

···
       bus. The device can be a NAND chip, SRAM device, NOR device
       or an ASIC.
     $ref: ti,gpmc-child.yaml
-
+    additionalProperties: true
 
 required:
   - compatible