Fix compile warning:

	..\..\libcpu\arm\cortex-m3\context_rvds.S(207):
	warning: A1581W: Added 2 bytes of padding at address 0xd6

libcpu/arm/cortex-m3/context_rvds.S

@@ -203,4 +203,5 @@ HardFault_Handler    PROC
     BX      lr
     ENDP
 
-    END
+    NOP
+    END
\ No newline at end of file