the purpose of this patch is to consider IOMMU support in the future.
EXYNOS4 SoC supports IOMMU also so the address for DMA could be
physical address with IOMMU or device address with IOMMU.
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>