PM / Domains: Fix build for CONFIG_PM_RUNTIME unset

Function genpd_queue_power_off_work() is not defined for
CONFIG_PM_RUNTIME, so pm_genpd_poweroff_unused() causes a build
error to happen in that case.  Fix the problem by making
pm_genpd_poweroff_unused() depend on CONFIG_PM_RUNTIME too.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 21097cb..f9ec173 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -72,8 +72,6 @@
 extern void pm_genpd_init(struct generic_pm_domain *genpd,
 			  struct dev_power_governor *gov, bool is_off);
 extern int pm_genpd_poweron(struct generic_pm_domain *genpd);
-extern void pm_genpd_poweroff_unused(void);
-extern void genpd_queue_power_off_work(struct generic_pm_domain *genpd);
 #else
 static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
 				      struct device *dev)
@@ -101,8 +99,14 @@
 {
 	return -ENOSYS;
 }
-static inline void pm_genpd_poweroff_unused(void) {}
+#endif
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS_RUNTIME
+extern void genpd_queue_power_off_work(struct generic_pm_domain *genpd);
+extern void pm_genpd_poweroff_unused(void);
+#else
 static inline void genpd_queue_power_off_work(struct generic_pm_domain *gpd) {}
+static inline void pm_genpd_poweroff_unused(void) {}
 #endif
 
 #endif /* _LINUX_PM_DOMAIN_H */