msm: smem: Add Dynamic SMEM Region Configuration

The static allocation of smem region's physical address and
total size creates image dependencies.

Adding dynamic smem region configuration removes image dependencies
and allows the memory map to be more easily modified during bringups.

Change-Id: I7b7555b6c446cdaef4f7bbfc920fb4965efcea23
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>