We'll soon merge <asm-generic/dma-mapping-common.h> into
<linux/dma-mapping.h> and the reference to dma_capable in the tile
dma_set_mask would create a circular dependency.

Fix this by moving the implementation out of line.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>