cpuidle: psci: Opt-out from genpd's common ->sync_state() support

The cpuidle-psci-domain implements its own specific ->sync_state()
callback. Let's set the GENPD_FLAG_NO_SYNC_STATE to inform genpd about it.

Moreover, let's call of_genpd_sync_state() to make sure genpd tries to
power off unused PM domains.

Tested-by: Hiago De Franco <hiago.franco@toradex.com> # Colibri iMX8X
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # TI AM62A,Xilinx ZynqMP ZCU106
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250701114733.636510-11-ulf.hansson@linaro.org

Author: Ulf Hansson

drivers/cpuidle/cpuidle-psci-domain.c

@@ -63,7 +63,8 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 	if (!pd_provider)
 		goto free_pd;
 
-	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
+	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN |
+		     GENPD_FLAG_NO_SYNC_STATE;
 
 	/*
 	 * Allow power off when OSI has been successfully enabled.
@@ -128,11 +129,16 @@ static void psci_pd_remove(void)
 
 static void psci_cpuidle_domain_sync_state(struct device *dev)
 {
+	struct psci_pd_provider *pd_provider;
+
 	/*
 	 * All devices have now been attached/probed to the PM domain topology,
 	 * hence it's fine to allow domain states to be picked.
 	 */
 	psci_pd_allow_domain_state = true;
+
+	list_for_each_entry(pd_provider, &psci_pd_providers, link)
+		of_genpd_sync_state(pd_provider->node);
 }
 
 static const struct of_device_id psci_of_match[] = {