[libc] Add mode_t in rtlibc.h for Keil MDK/IAR.

components/dfs/include/dfs.h

@@ -29,7 +29,6 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
 
 #include <time.h>
 #include <rtthread.h>

components/libc/compilers/armlibc/sys/types.h

@@ -9,6 +9,4 @@ typedef rt_int32_t key_t;       /* Used for interprocess communication. */
 typedef rt_int32_t pid_t;       /* Used for process IDs and process group IDs. */
 typedef signed long ssize_t;    /* Used for a count of bytes or an error indication. */
 
-typedef int mode_t;
-
 #endif

components/libc/compilers/dlib/sys/types.h

@@ -9,6 +9,4 @@ typedef rt_int32_t key_t;       /* Used for interprocess communication. */
 typedef rt_int32_t pid_t;       /* Used for process IDs and process group IDs. */
 typedef signed long ssize_t;    /* Used for a count of bytes or an error indication. */
 
-typedef int mode_t;
-
 #endif

include/rtlibc.h

@@ -36,6 +36,7 @@
 
 #if defined(__CC_ARM) || defined(__IAR_SYSTEMS_ICC__)
 typedef signed long off_t;
+typedef int mode_t;
 #endif
 
 #if defined(__MINGW32__)