Settings: Apply Processor settings to all cpus

QCOMs multicore implementation allows for different governors
and min/max values per cpu. Let the Settings app live up to the
user's assumed expectation and keep values synced across all
available cpus.

While this can be easily accomplished with a root-app, there are
a few prerequisites for our application: This patch requires
ueventd rules for cpu*/cpufreq/scaling_* files and write perms
to cpu*/online for the SYSTEM user in init.${ro.hardware}.rc.

Change-Id: Ic9349977f02282649a11319758dd7f546538f149