dt-bindings: arm64: dts: airoha: Add en7581 entry

Introduce Airoha EN7581 entry in Airoha dts binding.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/ee9cda964dac62d38d1c239f7b189f707d3708a0.1709975956.git.lorenzo@kernel.orgSigned-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Documentation/devicetree/bindings/arm/airoha.yaml

@@ -22,6 +22,10 @@ properties:
           - enum:
               - airoha,en7523-evb
           - const: airoha,en7523
+      - items:
+          - enum:
+              - airoha,en7581-evb
+          - const: airoha,en7581
 
 additionalProperties: true