tools/power turbostat: Move verbose counter messages to level 2

Printing information about the source and value during initialization and
reading of the counter for each cpu, while useful when debugging,
results in too verbose output.

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