A fixed y-axis scale was missed during a change to autoscale.
Correct it.
Fixes: 709bd70d07 ("tools/power/x86/intel_pstate_tracer: change several graphs to autoscale y-axis")
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>