Due to the way allocations are performed, over mapping must be disallowed. Otherwise, it may be possible to inadvertently unmap other physical addresses. The smallest length that can now be mapped is 4K. Lengths less than 4k can be safely overmapped since physical addresses must be 4k aligned as well. Change-Id: I897f479c0cec29d499406b52b624a6f2b34b718a Signed-off-by: Laura Abbott <lauraa@codeaurora.org>