dt-bindings: serial: pl011: allow ARM Primecell properties

Reference ARM Primecell bindings to allow typical Primecell device node properties:

  broadcom/bcm2711-rpi-400.dtb: serial@7e201000: Unevaluated properties are not allowed ('arm,primecell-periphid' was unexpected)
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20230124091916.45054-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/pl011.yaml

@@ -10,6 +10,7 @@ maintainers:
   - Rob Herring <robh@kernel.org>
 
 allOf:
+  - $ref: /schemas/arm/primecell.yaml#
   - $ref: serial.yaml#
 
 # Need a custom select here or 'arm,primecell' will match on lots of nodes