UPSTREAM: rcu: Track laziness during boot and suspend

Boot and suspend/resume should not be slowed down in kernels built with
CONFIG_RCU_LAZY=y.  In particular, suspend can sometimes fail in such
kernels.

This commit therefore adds rcu_async_hurry(), rcu_async_relax(), and
rcu_async_should_hurry() functions that track whether or not either
a boot or a suspend/resume operation is in progress.  This will
enable a later commit to refrain from laziness during those times.

Export rcu_async_should_hurry(), rcu_async_hurry(), and rcu_async_relax()
for later use by rcutorture.

[ paulmck: Apply feedback from Steve Rostedt. ]

Bug: 258241771
Bug: 222463781
Test: CQ
Fixes: 3cb278e7 ("rcu: Make call_rcu() lazy to save power")
Change-Id: Ieb2f2d484a33cfbd71f71c8e3dbcfc05cd7efe8c
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
(cherry picked from commit 6efdda8b)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4318051


Reviewed-by: Vineeth Pillai <vineethrp@google.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Tested-by: Joel Fernandes <joelaf@google.com>
Commit-Queue: Joel Fernandes <joelaf@google.com>
(cherry picked from commit 8bc7efc64c84da753f2174a7071c8f1a7823d2bb)
[Cherry picked from chromeos-5.15 tree. Minor tweaks to commit message
to match Android style]
Signed-off-by: Qais Yousef <qyousef@google.com>