[Kernel] Update version number.

include/rtdef.h

@@ -31,6 +31,7 @@
  *                             add smp relevant macros
  * 2019-01-27     Bernard      change version number to v4.0.1
  * 2019-05-17     Bernard      change version number to v4.0.2
+ * 2019-12-20     Bernard      change version number to v4.0.3
  */
 
 #ifndef __RT_DEF_H__
@@ -52,7 +53,7 @@ extern "C" {
 /* RT-Thread version information */
 #define RT_VERSION                      4L              /**< major version number */
 #define RT_SUBVERSION                   0L              /**< minor version number */
-#define RT_REVISION                     2L              /**< revise version number */
+#define RT_REVISION                     3L              /**< revise version number */
 
 /* RT-Thread version */
 #define RTTHREAD_VERSION                ((RT_VERSION * 10000) + \