As DMA code is the only user of IOMMU code both files can be merged.
It allows to remove stub functions, after slight adjustment of
exynos_drm_register_dma. Since IOMMU functions are used locally they
can be marked static.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>