Pull dma-mapping updates from Christoph Hellwig:
"Very light this round as the interesting dma mapping changes went
through the x86 tree.
This just provides proper stubs for architectures not supporting dma
(Geert Uytterhoeven)"
* tag 'dma-mapping-4.17' of git://git.infradead.org/users/hch/dma-mapping:
usb: gadget: Add NO_DMA dummies for DMA mapping API
scsi: Add NO_DMA dummies for SCSI DMA mapping API
mm: Add NO_DMA dummies for DMA pool API
dma-coherent: Add NO_DMA dummies for managed DMA API
dma-mapping: Convert NO_DMA get_dma_ops() into a real dummy