tools/power turbostat: Add --no-perf option

Add the --no-perf option to allow users to run turbostat without
accessing perf.

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