Merge branch 'drm-rockchip-next-2017-02-16' of https://github.com/markyzq/kernel-drm-rockchip into drm-next

Use iommu for rockchip arm64 platform.

* 'drm-rockchip-next-2017-02-16' of https://github.com/markyzq/kernel-drm-rockchip:
  drm/rockchip: Use common IOMMU API to attach devices
  drm/rockchip: Do not use DMA mapping API if attached to IOMMU domain