If you're right about the patch, that makes sense to me. So:
git remote add nss https://github.com/Ansuel/openwrt.git
git fetch nss
git checkout -b my-nss nss/kernel5.4-nss-qsdk10.0
git revert e168f9106a74bfd33ccca2a5f867652fb9caf073
git checkout master
git checkout -b my-master
git rebase my-nss
git add target/linux/ipq806x/files/include/net/netfilter/nf_conntrack_dscpremark_ext.h target/linux/ipq806x/files/include/uapi/linux/tc_act/tc_nss_mirred.h target/linux/ipq806x/files/net/netfilter/nf_conntrack_dscpremark_ext.c
git rebase --continue