doc: fix broken references

There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/input/input.txt b/Documentation/input/input.txt
index b93c084..b3d6787 100644
--- a/Documentation/input/input.txt
+++ b/Documentation/input/input.txt
@@ -111,7 +111,7 @@
 
  The monitor and speaker controls should be easy to add to the hid/input
 interface, but for the UPSs and LCDs it doesn't make much sense. For this,
-the hiddev interface was designed. See Documentation/usb/hiddev.txt
+the hiddev interface was designed. See Documentation/hid/hiddev.txt
 for more information about it.
 
   The usage of the usbhid module is very simple, it takes no parameters,