SLW: Delay cpuidle device-tree creation

Create cpuidle device-tree after slw_init(), so that we can stop the
deeper states from being added , when wakeup engine is not present or
failed.

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

core/opal.c

@@ -412,7 +412,6 @@ void add_opal_node(void)
 	add_opal_firmware_node();
 	add_associativity_ref_point();
 	memcons_add_properties();
-	add_cpu_idle_state_properties();
 }
 
 static struct lock evt_lock = LOCK_UNLOCKED;

hw/slw.c

@@ -1705,4 +1705,5 @@ void slw_init(void)
 		for_each_chip(chip)
 			slw_init_chip_p9(chip);
 	}
+	add_cpu_idle_state_properties();
 }