arm: dma-mapping: add dma mapper for io-pgtable-fast for 32 bit

io-pgtable-fast was implemented to achieve
better performance for IOMMU map/un-map. Add
DMA API support that goes through io-pgtable-fast
for 32 bit targets.

Change-Id: I3d0560a4331f6b7b87c70d0885df11d12cb1d6ec
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
[qqzhou@codeaurora.org: Reorganize codes to be more clear]
Signed-off-by: Qingqing Zhou <qqzhou@codeaurora.org>