cpupower: cpupower monitor reports uninitialized values for offline cpus

[root@hp-dl980g7-02 linux]# cpupower monitor
...
5472|   0|   1|******|******|******|******|| 0.00|  0.00|  0.00|  0.00|  0.00 *is offline
10567|   0| 159|******|******|******|******||  0.00|  0.00|  0.00|  0.00|  0.00 *is offline
1661206560|859272560| 150|******|******|******|******|| 0.00|  0.00|  0.00|  0.00|  0.00 *is offline
1661206560|943093104| 140|******|******|******|******|| 0.00|  0.00|  0.00|  0.00|  0.00 *is offline

because of this cpupower also holds the incorrect value for the number
of physical packages in the machine

Changed cpupower to initialize the values of an offline cpu's socket and
core to -1, warn the user that one or more cpus is/are
offline and not print statistics for offline cpus.

This fix hides offlined cores where topology cannot be accessed.
With a recent kernel patch suggested from Prarit Bhargava it may be possible
that soft offlined cores' topology can still be parsed.
This patch would then show which cores in which package/socket are offline,
when sane toplogoy information is available.

Signed-off-by: Jacob Tanenbaum <jtanenba@redhat.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>