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.

Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
[markivx: Fixed trivial makefile conflict]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

Change-Id: I491d584da0d5068fb11c8df556d9a1683bf418c7
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>