arm: dma: Allow CMA pages to not have a kernel mapping.

arm: dma: Allow CMA pages to not have a kernel mapping.

Currently, there are use cases where not having any kernel
mapping is required; if the CMA memory needs to be used as
a pool which can have both cached and uncached mappings we
need to remove the mapping to avoid the multiple mapping
problem. Extend the dma APIs to use the DMA_ATTR_NO_KERNEL_MAPPING
with CMA. This doesn't end up saving any virtual address space
but the mapping will still not be present.

Change-Id: I64d21250abbe615c43e2b5b1272ee2b6d106705a
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>