tools/power turbostat: Allow mapping multiple PMT files with the same GUID

Some platforms may expose multiple telemetry files identified with the
same GUID. Interpreting it correctly, to associate given counter with a
CPU, core or a package requires more metadata from the user.

Parse and create  ordered, linked list of those PMT aggregators, so that
we can identify specific aggregator with GUID + sequence number.

Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>