This patch introduces the driver for Shared-Data-Structure (SDS)
framework which will be used for communication between SCP and AP
CPU. The SDS framework is intended to replace the Boot-Over-MHU
(BOM) protocol used currently for the communication

Change-Id: Ic174291121f4e581b174cce3389d22d6435f7269
Signed-off-by: Soby Mathew <soby.mathew@arm.com>