intel_cpu_cstate(4): New driver, reports CPU-specific C-states residency

[olce]

Summary

This new driver reports residency counters for CPU-specific C-states,
for all scopes available (core, module or package).

It is based on September 2026's issue of the Intel Software Developer
Manual Volume 4. All Intel CPUs up to Intel Core Series 2 are expected
to work, and it is likely that Intel Core Series 3 ones will also work
out-of-the-box.

Please see the manual page for more details.