rcu: Remove CONFIG_RCU_CPU_STALL_VERBOSE

The CONFIG_RCU_CPU_STALL_VERBOSE Kconfig parameter causes preemptible
RCU's CPU stall warnings to dump out any preempted tasks that are blocking
the current RCU grace period.  This information is useful, and the default
has been CONFIG_RCU_CPU_STALL_VERBOSE=y for some years.  It is therefore
time for this commit to remove this Kconfig parameter, so that future
kernel builds will always act as if CONFIG_RCU_CPU_STALL_VERBOSE=y.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --cc Documentation/RCU/stallwarn.txt
Simple merge

diff --cc kernel/rcu/tree_plugin.h
Simple merge

diff --cc lib/Kconfig.debug
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE01
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE02
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE02-T
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE03
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE04
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE05
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE06
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE07
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE08
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE08-T
Simple merge

diff --cc tools/testing/selftests/rcutorture/configs/rcu/TREE09
Simple merge

diff --cc tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
Simple merge