rcutorture: Avoid soft lockup during cpu stall

rcutorture: Avoid soft lockup during cpu stall

[ Upstream commit 5ff7c9f9d7e3e0f6db5b81945fa11b69d62f433a ]

If we use the module stall_cpu option, we may get a soft lockup warning
in case we also don't pass the stall_cpu_block option.

Introduce the stall_no_softlockup option to avoid a soft lockup on
cpu stall even if we don't use the stall_cpu_block option.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>