tools/power/x86/intel_pstate_tracer: change several graphs to autoscale y-axis

Processors have exceeded some of the fixed y-axis scale maximum values.
Change them to autoscale the y-axis.

Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>