PM / Domains: Use power.sybsys_data to reduce overhead

Currently pm_genpd_runtime_resume() has to walk the list of devices
from the device's PM domain to find the corresponding device list
object containing the need_restore field to check if the driver's
.runtime_resume() callback should be executed for the device.
This is suboptimal and can be simplified by using power.sybsys_data
to store device information used by the generic PM domains code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/arch/arm/mach-shmobile/pm-sh7372.c b/arch/arm/mach-shmobile/pm-sh7372.c
index 54d4d86..4aeca0a 100644
--- a/arch/arm/mach-shmobile/pm-sh7372.c
+++ b/arch/arm/mach-shmobile/pm-sh7372.c
@@ -114,11 +114,9 @@
 {
 	struct device *dev = &pdev->dev;
 
-	if (!dev->power.subsys_data) {
-		pm_clk_create(dev);
-		pm_clk_add(dev, NULL);
-	}
 	pm_genpd_add_device(&sh7372_pd->genpd, dev);
+	if (pm_clk_no_clocks(dev))
+		pm_clk_add(dev, NULL);
 }
 
 void sh7372_pm_add_subdomain(struct sh7372_pm_domain *sh7372_pd,