Ok, the issue in this case is that the package reports its architecture as
ar71xx, so that's what you need to add to your architecture file instead of
mips_74kc_dsp2. The name of this package's architecture comes from the old OpenWRT denominations.
ar71xx package works for me, but I was unfamiliar with the build system when I made it, so I suggest you try the
74kc package instead, which is the vanilla OpenWRT (older) version of the package. You may even try both, and see with which one you have the best performance.
Second disclaimer: I don't know how important IPv6 or multicast are in your deployment, but be advised that what causes the issue this package is "solving" is related to the establishment of GTKs, namely that hostapd doesn't set them properly in this earlier version, which by accident raises no error with the ath10k driver (this I've come to learn after trying to dig deeper into why this specific wpad version is needed, and after trying to diagnose some network issues). This means that you will most likely have either of two outcomes depending on the ath10k driver and firmware you are using (for more information see my post here on that, or the related GitHub issue related to this on the ath10k-ct repository):
- IPv6, multicast and client-to-client doesn't work for wireless clients. This happens with the default driver and the default firmware.
- IPv6, multicast and client-to-client work, but the VLANs are not isolated from each other regarding these packages. Besides leaking data, this is especially akward with IPv6, as your interfaces will get IPv6 addresses for all active VLANs. To trigger this scenario you need to use the ath10k-ct firmware and possibly also the ath10k-ct driver.
Unfortunately, there doesn't seem to be an easy fix for this problem (I'm still looking, but at the moment this is not high up in my list of priorities). If your network uses only IPv4, no multicast, and you consider wireless clients not being able to talk to each other a feature (or, alternatively, situation 2 above), this issue won't affect you.