Add Kconfig options for memory probe and remove

These are needed to support physical hotplug and hotremove on
ARM platforms which contain memory that may be powered on and off
(instead of physically inserting and removing the memory).

Change-Id: Id0e5442924612370cbc4067a964f82e7a8305b88
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
(cherry picked from commit d77db7e30a3b3e3d7eac98bcfd09919da9959827)

Conflicts:

	arch/arm/Kconfig