[libcpu][arm][cortex-m23] Change exception return call address to 0xFFFFFFFD

libcpu/arm/cortex-m23/context_gcc.S

@@ -137,7 +137,7 @@ pendsv_exit:
     /* restore interrupt */
     MSR     PRIMASK, R2
 
-    MOVS    R0, #0x04
+    MOVS    R0, #0x03
     RSBS    R0, R0, #0x00
     BX      R0
 /*

libcpu/arm/cortex-m23/context_iar.S

@@ -139,7 +139,7 @@ pendsv_exit
     ; restore interrupt
     MSR     PRIMASK, r2
 
-    MOVS    r0, #0x04
+    MOVS    r0, #0x03
     RSBS    r0, r0, #0x00
     BX      r0
 

libcpu/arm/cortex-m23/context_rvds.S

@@ -143,7 +143,7 @@ pendsv_exit
     ; restore interrupt
     MSR     PRIMASK, r2
 
-    MOVS    r0, #0x04
+    MOVS    r0, #0x03
     RSBS    r0, r0, #0x00
     BX      r0
     ENDP