arm64: mm: bug around swiotlb_dma_ops

[nikita.yoush@cogentembedded.com (Nikita Yushchenko)]

> If trying to avoid big changes and only fixing particular problem with
> particular device not working on arm64, I think best way is to
> alter__swiotlb_dma_supported() in arch/arm64/mm/dma-mapping.c to detect
> and decline (with -EIO) mask that is unsupported by device connection.
> This will cover both dma_mask and coherent_dma_mask.
> 
> This has to be combined with some way to explicitly extract information
> about limitations. Checking device parent's dma masks won't work unless
> somebody bothers to populate them.

I'm trying to bring together a patch doing this, will post that when ready