dt-bindings: usb: ci-hdrc-usb2: fix node node for ethernet controller

This documentation provides wrong node name for the Ethernet controller.
It should be "ethernet" instead of "smsc" as required by Ethernet
controller devicetree schema:
 Documentation/devicetree/bindings/net/ethernet-controller.yaml

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220517111505.929722-4-o.rempel@pengutronix.de