How to control Ethernet PHY without having Ethernet instance on device tree

We made a custom board using a Xavier NX module. This custom board is to join an existing system. The Ethernet link with the existing system is an RGMII link (type MAC link). As the Xavier NX module already has an Ethernet PHY which transforms the MAC link into an Ethernet link, we have therefore put on our custom board another Ethernet PHY (for reverse transofrmation).
My question concerns the use of 2 GPIO pins as MDIO. Have you ever controlled another Ethernet PHY from GPIOs with this module? do you have an mdio-gpio driver?
I want to use mdio-gpio driver. How to to add it on a dtsi file for Xavier Nx SOM using GPIO13 and GPIO14 ?
Thanks for your help.

Duplicated with How to control another Ethernet PHY by Xavier NX?