ARM: DMA-mapping: fix memory leak in IOMMU dma-mapping implementation

This patch removes page_address() usage in IOMMU-aware dma-mapping
implementation and replaced it with direct use of the cpu virtual address
provided by the caller. page_address() returned incorrect address for
pages remapped in atomic pool, what caused memory leak.

Reported-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Hiroshi Doyu <hdoyu@nvidia.com>