doc: fix wrong arch/i386 references

Change all "arch/i386" to "arch/x86" in Documentaion/,
since the directory has changed.

Also update the files which have changed their filename
in the meantime accordingly.

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
[jkosina@suse.cz: reword changelog]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/scsi/BusLogic.txt b/Documentation/scsi/BusLogic.txt
index d7fbc94..48e982c 100644
--- a/Documentation/scsi/BusLogic.txt
+++ b/Documentation/scsi/BusLogic.txt
@@ -553,7 +553,7 @@
   make config
   make zImage
 
-Then install "arch/i386/boot/zImage" as your standard kernel, run lilo if
+Then install "arch/x86/boot/zImage" as your standard kernel, run lilo if
 appropriate, and reboot.