arm64: dts: rockchip: add naneng combo phy nodes for rk3568

Add the core dt-node for the rk3568's naneng combo phys.

Signed-off-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Link: https://lore.kernel.org/r/20220208091326.12495-5-yifeng.zhao@rock-chips.com


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