iommu-fixes-v4.3-rc7

Two late fixes for the AMD IOMMU driver:

	* One adds an additional check to the io page-fault handler to
	  avoid a BUG_ON being hit in handle_mm_fault()

	* Second patch fixes a problem with devices writing to the
	  system management area and were blocked by the IOMMU because
	  the driver wrongly cleared out the DTE flags allowing that
	  access.