Ipq806x NSS build (Netgear R7800 / TP-Link C2600 / Linksys EA8500)

[sppmaster]

New fix by @Ansuel here

[PR] ipq806x: kernel 5.10 bump code propose

@hnyman @remittor sorry for the regression, I just have pushed the fix in master and openwrt-22.03. My bad of assuming that sysfs to be cpufreq generic... quite the opposite as every cpufreq driver needs to declare it in their dedicated sysfs attr.