iommu/amd: Don't use MSI address range for DMA addresses

[ upstream commit 17f5b569 ]

Reserve the MSI address range in the address allocator so
that MSI addresses are not handed out as dma handles.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>