[NANO130] Fix symbol of IAR toolchain

Author: ccchang12

targets/TARGET_NUVOTON/nu_bitutil.h

@@ -17,7 +17,7 @@
 #ifndef NU_BIT_UTIL_H
 #define NU_BIT_UTIL_H
 
-#if defined(TOOLCHAIN_IAR) && defined(TARGET_M0)
+#if defined(__ICCARM__) && defined(TARGET_M0)
 #include <arm_math.h>
 #endif
 #include "cmsis.h"