@kestrel exactly the mac80211.ko is not needed for rlt driver itself. It's enough to have cfg80211.ko which is loaded as dependency to 8189fs.ko.
I've tried to use both files from Armbian, but cfg80211.ko need satisfy dependency to rfkill, which is not available in OpenWrt source.
To have compatible kernel, I've tried to use the Armbian's /boot, but even the kernel starts, it halts somewhere and then reboots. But don't know what happens, because there is not output on the serial.
There is only:
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
[ 43.857279] reboot: Restarting system
Edit. This is the full verbosity output:
[ 4.273669] sunxi-mmc 1c10000.mmc: allocated mmc-pwrseq
[ 4.509368] sunxi-mmc 1c10000.mmc: initialized, max. request size: 16384 KB
[ 4.534267] mmc1: new high speed SDIO card at address 0001
[ 4.801465] random: fast init done
[ 45.532057] reboot: Restarting system
No idea, what is random function which probably cause system halt.
The reboot is than probably caused by watchdog.