PM / Domains: Make pm_genpd_{add,remove}_subdomain() available to modules

Export these symbols so they can be used in loadable kernel
modules.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Rajendra Nayak <rnayak@codeaurora.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/base/power/domain.c

@@ -1427,6 +1427,7 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
 
 /**
  * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
@@ -1503,6 +1504,7 @@ out:
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
 
 /**
  * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.