Frequency-invariant utilization tracking for x86

There is generally this notion that has existed for too long that frequency control is the only thing to be concerned about. In reality, there's a lot more an OS/platform can collaborate on, from frequency, to thermal pressure. On Arm servers, the CPPC extension to ACPI allows some of this to be enabled in a generic way and AMD extended this spec in their Zen2+ designs also. I would like to see generic CPPC/schedutil integration and adoption of such specs beyond just Arm platforms. To include thermal pressure and many other aspects as well. To that end, I'm planning for us to do some work on this and propose standard solutions in the months ahead. Very keen to hear from others who would like to discuss gaps in the current generic standards and how to plug those with a cross-industry solution.