switch nios2 and microblaze to use the generic uncached segement support

[Christoph Hellwig]

Hi all,

can you take a look at this series?  It switches niops2 and microblaze to
use the generic dma layer support for uncached segements.

The dma mapping for-next git tree that includes the support is available
here:

    git://git.infradead.org/users/hch/dma-mapping.git for-next

Gitweb:

    http://git.infradead.org/users/hch/dma-mapping.git/shortlog/refs/heads/for-next