Using sdk to build old version of kmod-ath9k

The latest ath9k driver, which is from backports, does not detect the AR9462 that was once detected. I have an image that detects it that was built before May 1st.

How can I build an older version of kmod-ath9k with the sdk builder, so I can test an older working driver with a newer kernel?

Just FYI

lspci finds it

03:00.0 Network controller: Qualcomm Atheros AR9462 Wireless Network Adapter (rev 01)

The module loads

root@LEDE:~# lsmod | grep ath
ath                    16787  3 ath9k,ath9k_common,ath9k_hw
ath9k                  95491  0 
ath9k_common           21286  1 ath9k
ath9k_hw              332780  2 ath9k,ath9k_common
cfg80211              199536  4 ath9k,ath9k_common,ath,mac80211
compat                  4848  4 ath9k,ath9k_common,mac80211,cfg80211
mac80211              375591  1 ath9k

dmesg says

[  144.196921] Loading modules backported from Linux version wt-2017-11-01-0-gfe248fc2c180
[  144.205077] Backport generated by backports.git v4.14-rc2-1-31-g86cf0e5d

That is weird since AR9462 was not touched for a long time

I tried modprobe ath9k btcoex_enable=0, but no change. Maybe that's not the right way to do it, because debug=1 did not make /sys/proc/debug/ieee* appear either.