tools/power turbostat: decode HWP registers

 # turbostat --debug
...
CPUID(6): ... HWP, HWPnotify, HWPwindow, HWPepp, HWPpkg ...
...
cpu0: MSR_PM_ENABLE: 0x00000001 (HWP)
cpu0: MSR_HWP_CAPABILITIES: 0x01050916 (high 0x16 guar 0x9 eff 0x5 low 0x1)
cpu0: MSR_HWP_REQUEST: 0x80001604 (min 0x4 max 0x16 des 0x0 epp 0x80 window 0x0 pkg 0x0)
cpu0: MSR_HWP_INTERRUPT: 0x00000001 (EN_Guaranteed_Perf_Change, Dis_Excursion_Min)
cpu0: MSR_HWP_STATUS: 0x00000000 (No-Guaranteed_Perf_Change, No-Excursion_Min)

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