Revert "Francisco is right, onlining all cores is a nice workaround for the real problem."

This reverts commit a4c8cb181f58fae8dc8ac9273338a3bfe9a793e7.
Revert "Fix up some various naming issues after inclusion of max_online_cpus code"

This reverts commit da0be3fd9f14773e933ac25a5672a78ddd32670c.
Revert "Add max_online_cpus feature"

This reverts commit 965ce947bd575c7d2f00ccb7eacb6e4043994bcc.
Revert "auto_hotplug: some tweaks"

This reverts commit ff4a8b14affc2a868f71a57ca6e2d7a844bf28df.
Revert "auto_hotplug: enable the min_online_cpus value"

This reverts commit 3178ed78c8ad263450a16233d7388051eb840f77.
Revert "ARM: add auto hotplug driver"

This reverts commit ff20f7806915c202a21179e2165d7bf4f5b0d7b5.