PM / runtime: Fix autosuspend documentation

Update the autosuspend documentation which claimed that the autosuspend
delay is not taken into account when using the non-autosuspend helper
functions, something which is no longer true since commit d66e6db28df3
("PM / Runtime: Respect autosuspend when idle triggers suspend").

This specifically means that drivers must now disable autosuspend before
disabling runtime pm in probe error paths and remove callbacks if
pm_runtime_put_sync was being used to suspend the device before
returning. (If an idle callback can prevent suspend,
pm_runtime_put_sync_suspend must be used instead of pm_runtime_put_sync
as before.)

Also remove the claim that the autosuspend helpers behave "just like
the non-autosuspend counterparts", something which have never really
been true as some of the latter use idle notifications.

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/power/runtime_pm.txt

@@ -836,9 +836,8 @@ of the non-autosuspend counterparts:
 	Instead of: pm_runtime_put_sync   use: pm_runtime_put_sync_autosuspend.
 
 Drivers may also continue to use the non-autosuspend helper functions; they
-will behave normally, not taking the autosuspend delay into account.
-Similarly, if the power.use_autosuspend field isn't set then the autosuspend
-helper functions will behave just like the non-autosuspend counterparts.
+will behave normally, which means sometimes taking the autosuspend delay into
+account (see pm_runtime_idle).
 
 Under some circumstances a driver or subsystem may want to prevent a device
 from autosuspending immediately, even though the usage counter is zero and the