Revert "auto_hotplug: Add tunable parameters enable/min sampling rate, set min"

This reverts commit 149e7ed1096aa2c2aa845e8cdcac9f8555180d2f.
Revert "auto_hotplug: initial min sampling rate at initialization and change"

This reverts commit 843810a19a6f85a0bcab7a8a059ca13e13f08079.
auto_hotplug: some tweaks
Several tweaks to try to improve battery life.
Francisco is right, onlining all cores is a nice workaround for the real problem.
Onlining all cores using the driver's framework.
Some whitespace cleanup.