dt-bindings: net: bcm4908-enet: include ethernet-controller.yaml

It should be /included/ by every Ethernet controller binding. It adds
support for various generic properties.
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/brcm,bcm4908-enet.yaml

@@ -11,6 +11,9 @@ description: Broadcom's Ethernet controller integrated into BCM4908 family SoCs
 maintainers:
   - Rafał Miłecki <rafal@milecki.pl>
 
+allOf:
+  - $ref: ethernet-controller.yaml#
+
 properties:
   compatible:
     const: brcm,bcm4908-enet