[PATCH] cpuidle: Measure idle state durations with monotonic clock

[Julius Werner]

> Maybe you can remove all these computations and set the flag
> en_core_tk_irqen for the driver ? That will be handled by the cpuidle
> framework, no ?
>
> Same comment for the intel_idle driver.

Yeah, I thought about that, too. I was a little too afraid of touching
the sched_clock_idle_wakeup_event() parameter that is tied to the
measurement, but it seems to have been vestigial for some time now and
other drivers also just set it 0. I will whip up another version of
the patch (won't change the PPC further though, if this version works
I would just leave it at that... thanks for testing, Deepthi).