rcu: Switch to exedited grace periods for suspend as well as hibernation

rcu: Switch to exedited grace periods for suspend as well as hibernation

Commit 587ff2cf ("rcu: Expedite grace periods during suspend/resume")
enabled expedited grace periods for hibernation, but not for suspend.
The same issue applies to both cases, so this commit simply applies the
same logic by adding additional cases to the switch statement.

Note that this commit also switches from PM_POST_RESTORE to the
combination of PM_POST_HIBERNATION and PM_POST_SUSPEND.  A separate
patch from Borislav Petkov corrects the documentation to indicate that
this is necessary.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>