X86 timer specific updates: - Add TPAUSE based delay which allows the CPU to enter an optimized power state while waiting for the delay to pass. The delay is based on TSC cycles. - Add tsc_early_khz command line parameter to workaround the problem that overclocked CPUs can report the wrong frequency via CPUID.16h which causes the refined calibration to fail because the delta to the initial frequency value is too big. With the parameter users can provide an halfways accurate initial value.