Introduce rculist.h

In linux-next there is a commit ("rcu: split list.h and move rcu-protected
lists into rculist.h") that moved the rcu related list iterators from
list.h to rculist.h.  Add a trivial version of the file now so that
various subsystem trees can start using it now for -next changes and so
reduce the build errors caused by adding uses of the moved functions.

Cc: Franck Bui-Huu <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Cc: Josh Triplett <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/linux/rculist.h

@@ -0,0 +1,6 @@
+#ifndef _LINUX_RCULIST_H
+#define _LINUX_RCULIST_H
+
+#include <linux/list.h>
+
+#endif	/* _LINUX_RCULIST_H */