PM / Domains: Provide dummy governors if CONFIG_PM_GENERIC_DOMAINS=n

This allows to compile-test drivers that refer to governors (always by
reference) when CONFIG_PM_GENERIC_DOMAINS=n.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

include/linux/pm_domain.h

@@ -182,6 +182,9 @@ static inline int pm_genpd_remove(struct generic_pm_domain *genpd)
 {
 	return -ENOTSUPP;
 }
+
+#define simple_qos_governor		(*(struct dev_power_governor *)(NULL))
+#define pm_domain_always_on_gov		(*(struct dev_power_governor *)(NULL))
 #endif
 
 static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,