docs: fix broken doc references due to renames

Some files got renamed but probably due to some merge conflicts,
a few references still point to the old locations.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index 045bb81..1adbb8a 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -548,7 +548,7 @@
 
 	[*] For information on bus mastering DMA and coherency please read:
 
-	    Documentation/PCI/pci.rst
+	    Documentation/driver-api/pci/pci.rst
 	    Documentation/DMA-API-HOWTO.txt
 	    Documentation/DMA-API.txt