SPM: Add a panic after NS jumping

In general the NS jumping should never return. Add a painc
after jump in case a failed jumping would run to random places.

Change-Id: I3b1bbdede91c4335bb4ee0b58bdd2a773456158b
Signed-off-by: Ken Liu <ken.liu@arm.com>
diff --git a/secure_fw/spm/cmsis_func/arch.c b/secure_fw/spm/cmsis_func/arch.c
index b237e16..c615d13 100644
--- a/secure_fw/spm/cmsis_func/arch.c
+++ b/secure_fw/spm/cmsis_func/arch.c
@@ -20,6 +20,8 @@
 {
     /* Calls the non-secure Reset_Handler to jump to the non-secure binary */
     ns_entry();
+
+    tfm_core_panic();
 }
 
 __attribute__((naked))