tools/power turbostat: cpu0 is no longer hard-coded, so update output

The --debug option reads a number of per-package MSRs.
Previously we explicitly read them on cpu0, but recently
turbostat changed to read them on the current "base_cpu".

Update the print-out to reflect base_cpu, rather than
the hard-coded cpu0.

Signed-off-by: Len Brown <len.brown@intel.com>