DMA-related cleanups for parisc

From: Christoph Hellwig
Date: Mon Jan 14 2019 - 06:24:01 EST


Hi James and Helge,

this series has a couple DMA-related cleanups for parisc. The main aim
is to move anything not required by drivers out of <asm/dma-mapping.h>,
but I noticed a few related bits and cleaned them up as well.