sched/core_ctl: Integrate core control with cpu isolation

Replace hotplug functionality in core control with cpu isolation
and integrate into scheduler.

Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
[markivx: Fixed minor header include conflict and no HMP]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

Change-Id: I28a740f7e019db94b7b885533dc2cfbf6ddd7bae
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>