PM / Domains: Change prototype for the attach and detach callbacks

Convert the prototypes to return an int in order to support error
handling in these callbacks.

Also, as suggested by Dmitry Torokhov, pass the domain pointer for use
inside the callbacks, and so that they match the existing
power_on/power_off callbacks which currently take the domain pointer.

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ khilman: added domain as parameter to callbacks, as suggested by Dmitry ]
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 73e938b..b3ed776 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -72,8 +72,10 @@
 	bool max_off_time_changed;
 	bool cached_power_down_ok;
 	struct gpd_cpuidle_data *cpuidle_data;
-	void (*attach_dev)(struct device *dev);
-	void (*detach_dev)(struct device *dev);
+	int (*attach_dev)(struct generic_pm_domain *domain,
+			  struct device *dev);
+	void (*detach_dev)(struct generic_pm_domain *domain,
+			   struct device *dev);
 };
 
 static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)