dt-bindings: net: dsa: mediatek,mt7530: remove unnecessary dsa-port reference

dsa.yaml contains a reference to dsa-port.yaml, so a duplicate reference to
the binding isn't necessary. Remove this unnecessary reference.
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -165,7 +165,6 @@ patternProperties:
               for user ports.
 
         allOf:
-          - $ref: dsa-port.yaml#
           - if:
               required: [ ethernet ]
             then: