We need to pass a struct device to the DMA API, even if some architectures
still support that for legacy reasons, and should not mix it with the old
PCI DMA API.

Note that the driver also seems to never actually unmap its DMA mappings,
but to fix that we'll need someone more familar with the driver.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>