PM / Domain: Add struct device to genpd

The power-domain core would be using the OPP core going forward and the
OPP core has the basic requirement of a device structure for its working.

Add a struct device to the genpd structure. This doesn't register the
device with device core as the "dev" pointer is mostly used by the OPP
core as a cookie for now and registering the device is not mandatory.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 04dbef9..aaacaa3 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -49,6 +49,7 @@ struct genpd_power_state {
 struct genpd_lock_ops;
 
 struct generic_pm_domain {
+	struct device dev;
 	struct dev_pm_domain domain;	/* PM domain operations */
 	struct list_head gpd_list_node;	/* Node in the global PM domains list */
 	struct list_head master_links;	/* Links with PM domain as a master */