All drivers should be using dma_set_mask / pci_set_dma_mask to try to
set the dma mask instead of just querying it. Without that some iommu
implementations may not work.
pci_dma_supported is removed entirely, but dma_supported stays for
dma_ops implementations for now.
This patch (of 15):
This ensures the dma mask that is supported by the driver is recorded
in the device structure.