tools/power turbostat: print more turbo-limit information

The "turbo-limit" is the maximum opportunistic processor
speed, assuming no electrical or thermal constraints.
For a given processor, the turbo-limit varies, depending
on the number of active cores.  Generally, there is more
opportunity when fewer cores are active.

Under the "-v" verbose option, turbostat would
print the turbo-limits for the four cases
of 1 to 4 cores active.

Expand that capability to cover the cases of turbo
opportunities with up to 16 cores active.

Note that not all hardware platforms supply this information,
and that sometimes a valid limit may be specified for
a core which is not actually present.

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