Documentation: move DMA-mapping.txt to Doc/PCI/

Move DMA-mapping.txt to Documentation/PCI/.

DMA-mapping.txt was supposed to be moved from Documentation/ to
Documentation/PCI/.  The 00-INDEX files in those two directories
were updated, along with a few other text files, but the file
itself somehow escaped being moved, so move it and update more
text files and source files with its new location.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
cc:	Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/parisc/include/asm/dma-mapping.h b/arch/parisc/include/asm/dma-mapping.h
index 53af696..da69433 100644
--- a/arch/parisc/include/asm/dma-mapping.h
+++ b/arch/parisc/include/asm/dma-mapping.h
@@ -5,7 +5,7 @@
 #include <asm/cacheflush.h>
 #include <asm/scatterlist.h>
 
-/* See Documentation/DMA-mapping.txt */
+/* See Documentation/PCI/PCI-DMA-mapping.txt */
 struct hppa_dma_ops {
 	int  (*dma_supported)(struct device *dev, u64 mask);
 	void *(*alloc_consistent)(struct device *dev, size_t size, dma_addr_t *iova, gfp_t flag);