[$] Frequency-invariant utilization tracking for x86

The kernel provides a number of CPU-frequency governors to choose from; bymost accounts, the most effective of those is "schedutil", which was merged for the 4.7kernel in 2016. While schedutil is used on mobile devices, it stilldoesn't see much use on x86 desktops; the intel_pstategovernor isgenerally seen giving better results on those processors as a result of thesecret knowledge embodied therein. A set of patches merged for 5.7, though,gives schedutil a better idea of what the true utilization of x86processors is and, as a result, greatly improves its effectiveness.