iommu-fixes-v5.0-rc4

A few more fixes this time:

	- Two patches to fix the error path of the map_sg implementation
	  of the AMD IOMMU driver.

	- Also a missing IOTLB flush is fixed in the AMD IOMMU driver.

	- Memory leak fix for the Intel IOMMU driver.

	- Fix a regression in the Mediatek IOMMU driver which caused
	  device initialization to fail (seen as broken HDMI output).