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/Documentation/IO-mapping.txt b/Documentation/IO-mapping.txt
index 86edb61..78a4406 100644
--- a/Documentation/IO-mapping.txt
+++ b/Documentation/IO-mapping.txt
@@ -1,6 +1,6 @@
 [ NOTE: The virt_to_bus() and bus_to_virt() functions have been
-	superseded by the functionality provided by the PCI DMA
-	interface (see Documentation/DMA-mapping.txt).  They continue
+	superseded by the functionality provided by the PCI DMA interface
+	(see Documentation/PCI/PCI-DMA-mapping.txt).  They continue
 	to be documented below for historical purposes, but new code
 	must not use them. --davidm 00/12/12 ]