Hello, @jock
After a bit of researching i found out that actually rockchip devices initialize wifi in rfkill and there are even some special drivers in kernel for it. I studied a source code of rfkill and saw there hardcoded names of device tree properties that are present in original device tree. There is armbian/linux-rockchip repository where those drivers are present. Maybe that's somehow could help with my case? Does your kernel image have them? Or is it dead end too?
Best regards)