arm64: dts: rockchip: Enable Ethernet for Radxa CM3 IO

Add ethernet nodes for enabling gmac1 on the Radxa CM3 IO board.

Signed-off-by: Manoj Sai <abbaraju.manojsai@amarulasolutions.com>
Link: https://lore.kernel.org/r/20230125161023.12115-1-jagan@amarulasolutions.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>