tools/power turbostat: disable "cpuidle" invocation counters, by default

Create "pct_idle" counter group, the sofware notion of residency
so it can now be singled out, independent of other counter groups.

Create "cpuidle" group, the cpuidle invocation counts.
Disable "cpuidle", by default.

Create "swidle" = "cpuidle" + "pct_idle".
Undocument "sysfs", the old name for "swidle", but keep it working
for backwards compatibilty.

Create "hwidle", all the HW idle counters

Modify "idle", enabled by default
"idle" = "hwidle" + "pct_idle" (and now excludes "cpuidle")

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