core_ctrl: Move core control into kernel

Move core control from out-of-tree module into the kernel proper.

Core control monitors load on CPUs and controls how many CPUs are
available for the system to use at any point in time. This can help save
power. Core control can be configured through sysfs interface.

Change-Id: Ia78e701468ea3828195c2a15c9cf9fafd099804a
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>