ARM: dts: exynos: fix ethernet node name for different odroid boards

ARM: dts: exynos: fix ethernet node name for different odroid boards

The node name of Ethernet controller should be "ethernet" instead of
"usbether" as required by Ethernet controller devicetree schema:
 Documentation/devicetree/bindings/net/ethernet-controller.yaml

This patch can potentially affect boot loaders patching against full
node path instead of using device aliases.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20220216074927.3619425-6-o.rempel@pengutronix.de
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>