locking/Documentation: Move locking related docs into Documentation/locking/

Specifically:
  Documentation/locking/lockdep-design.txt
  Documentation/locking/lockstat.txt
  Documentation/locking/mutex-design.txt
  Documentation/locking/rt-mutex-design.txt
  Documentation/locking/rt-mutex.txt
  Documentation/locking/spinlocks.txt
  Documentation/locking/ww-mutex-design.txt

Signed-off-by: Davidlohr Bueso <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Alexei Starovoitov <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Dan Streetman <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jason Low <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Lubomir Rintel <[email protected]>
Cc: Masanari Iida <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Documentation/DocBook/kernel-locking.tmpl

@@ -1972,7 +1972,7 @@ machines due to caching.
    <itemizedlist>
     <listitem>
      <para>
-       <filename>Documentation/spinlocks.txt</filename>: 
+       <filename>Documentation/locking/spinlocks.txt</filename>:
        Linus Torvalds' spinlocking tutorial in the kernel sources.
      </para>
     </listitem>