Revert "iommu/amd: Don't allocate with __GFP_ZERO in alloc_coherent"
This reverts commit 5fc872c7 . The DMA-API does not strictly require that the memory returned by dma_alloc_coherent is zeroed out. For that another function (dma_zalloc_coherent) should be used. But all other x86 DMA-API implementation I checked zero out the memory, so that some drivers rely on it and break when it is not. It seems the (driver-)world is not yet ready for this change, so revert it. Signed-off-by: Joerg Roedel <email@example.com>