power: declare power states unconditionally

Declare power management states unconditionally.
Should fix #13194.

Signed-off-by: Emanuele Di Santo <[email protected]>

Author: lemrey

include/power.h

@@ -14,10 +14,6 @@
 extern "C" {
 #endif
 
-#ifdef CONFIG_SYS_POWER_MANAGEMENT
-
-extern unsigned char sys_pm_idle_exit_notify;
-
 /**
  * @defgroup power_management_api Power Management
  * @{
@@ -56,6 +52,10 @@ enum power_states {
 	SYS_POWER_STATE_MAX
 };
 
+#ifdef CONFIG_SYS_POWER_MANAGEMENT
+
+extern unsigned char sys_pm_idle_exit_notify;
+
 /**
  * @brief System Power Management API
  *