* Support for Qualcomm Krait processors (run perf on your phone!)
* Support for Cortex-A12 (run perf stat on your FPGA!)
* Support for perf_sample_event_took, allowing us to automatically decrease
the sample rate if we can't handle the PMU interrupts quickly enough
(run perf record on your FPGA!).
As part of the Krait support, we also gain support for PPI generation by
the PMU.