Hello @tlamarc
You can refer to this thread.
There is mentioned that most of the peripherals are defined in imx7d.dtsi. NXP does not have any reference design to imx7s, so, you can check the reference manual to see the memory address and modify your device tree.
Also, you can base your device tree in imx7d.dtsi and remove the unsupported things by imx7s.
I hope this can helps to you.
Best regaeds.
Salas.