tools/rcutorture: Support nocb toggle in TREE01

This commit adds periodic toggling of 7 of 8 CPUs every second to TREE01
in order to test NOCB toggle code.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot

@@ -2,5 +2,7 @@ maxcpus=8 nr_cpus=43
 rcutree.gp_preinit_delay=3
 rcutree.gp_init_delay=3
 rcutree.gp_cleanup_delay=3
-rcu_nocbs=0
+rcu_nocbs=0-1,3-7
+rcutorture.nocbs_nthreads=8
+rcutorture.nocbs_toggle=1000
 rcutorture.fwd_progress=0