tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS

The Processor generation code-named Haswell
added MSR_{CORE | GFX | RING}_PERF_LIMIT_REASONS
to explain when and how the processor limits frequency.

turbostat -v
will now decode these bits.

Each MSR has an "Active" set of bits which describe
current conditions, and a "Logged" set of bits,
which describe what has happened since last cleared.

Turbostat currently doesn't clear the log bits.

Signed-off-by: Len Brown <len.brown@intel.com>