refactor dma_cache_sync V2

[Christoph Hellwig]

On Mon, Oct 16, 2017 at 02:44:42PM +0200, Christoph Hellwig wrote:
> On Tue, Oct 03, 2017 at 12:49:51PM +0100, Robin Murphy wrote:
> > Reviewed-by: Robin Murphy <robin.murphy at arm.com>
> 
> Thanks Robin.  I've heard very little from the arch maintainers,
> but if people remain silent I will apply the whole series to the
> dma-mapping tree in the next days.

Applied to the dma-mapping tree for 4.15.