cpufreq: stats: remove hotplug notifiers

Either CPUs are hot-unplugged or suspend/resume occurs, cpufreq core
will send notifications to cpufreq-stats and stats structure and sysfs
entries would be correctly handled..

And so we don't actually need hotcpu notifiers in cpufreq-stats anymore.
We were only handling cpu hot-unplug events here and that are already
taken care of by POLICY notifiers.

Change-Id: Icc5df84bdec5704976d24f14c36c8485bdbf0dce
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 027cc2e4a6127fdf29e17a422aacb5ecd9830cbb
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[junjiew@codeaurora.org: resolve merge conflict]
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>