dt-bindings: net: dsa: mediatek,mt7530: Add airoha,en7581-switch

Add documentation for the built-in switch which can be found in the
Airoha EN7581 SoC.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml

@@ -92,6 +92,10 @@ properties:
           Built-in switch of the MT7988 SoC
         const: mediatek,mt7988-switch
 
+      - description:
+          Built-in switch of the Airoha EN7581 SoC
+        const: airoha,en7581-switch
+
   reg:
     maxItems: 1
 
@@ -284,7 +288,9 @@ allOf:
   - if:
       properties:
         compatible:
-          const: mediatek,mt7988-switch
+          enum:
+            - mediatek,mt7988-switch
+            - airoha,en7581-switch
     then:
       $ref: "#/$defs/mt7530-dsa-port"
       properties: