exo: implement start of mariko fatal handler

exosphere/program/source/secmon_user_power_management.hpp

@@ -19,13 +19,15 @@
 namespace ams::secmon {
 
     enum UserRebootType {
-        UserRebootType_None      = 0,
-        UserRebootType_ToRcm     = 1,
-        UserRebootType_ToPayload = 2,
+        UserRebootType_None         = 0,
+        UserRebootType_ToRcm        = 1,
+        UserRebootType_ToPayload    = 2,
+        UserRebootType_ToFatalError = 3,
     };
 
     void PerformUserRebootToRcm();
     void PerformUserRebootToPayload();
+    void PerformUserRebootToFatalError();
     void PerformUserShutDown();
 
 }