power: bcl: Add support to use CPU phandles for hotplug

Add support in BCL module to use phandles to refer the
CPUs that are to be hotplugged during battery current
limiting conditions.

This removes the previous support for using the hotplug
bit mask to input the CPUs to be hotplugged.

Change-Id: I47cd0dd5fd719e75dd350822a796731a524960e0
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>