iommu/amd: Initialize device table after dma_ops

iommu/amd: Initialize device table after dma_ops

commit f528d980c17b8714aedc918ba86e058af914d66b upstream.

When dma_ops are initialized the unity mappings are created. The
init_device_table_dma() function makes sure DMA from all devices is
blocked by default. This opens a short window in time where DMA to
unity mapped regions is blocked by the IOMMU. Make sure this does not
happen by initializing the device table after dma_ops.

Tested on 3.2.38

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>