tools/power turbostat: add --out option for saving output in a file

tools/power turbostat: add --out option for saving output in a file

Orabug: 24811361

By default...

Turbostat --debug gconfiguration info goes to stderr.

In FORK mode, turbostat statistics go to stderr.

In PERIODIC mode, turbostat statistics go to stdout.

These defaults do not change, but an option "--out file"
will send all output above only to the specified file.

Signed-off-by: Len Brown <len.brown@intel.com>
(cherry picked from commit b7d8c1483bbf6ec9d2dd76d6a1c91a38c3f6ac35)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>