Merge pull request #4198 from c1728p9/fix_m0_on_iar

Fix IAR compilation for cortex-m0

Author: theotherjimmy

rtos/rtx2/TARGET_CORTEX_M/core_cm.h

@@ -31,6 +31,7 @@
 #include <stdint.h>
 #include "cmsis.h"
 #include "cmsis_compiler.h"
+#include "arm_math.h"
 
 #ifndef __ARM_ARCH_6M__
 #define __ARM_ARCH_6M__         0U