Documentation/SubmitChecklist: add RCU debug config options

There have been persistent lockdep RCU splats, indicating that submitters
are not testing with CONFIG_PROVE_RCU.  Add this config option to the list
in Documentation/SubmitChecklist.  Also add CONFIG_DEBUG_OBJECTS_RCU_HEAD
for good measure.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>