[libc] Remove fcntl.h in newlib porting.

components/dfs/include/dfs_def.h

@@ -108,6 +108,10 @@
 #define DFS_O_EXCL               O_EXCL
 #define DFS_O_TRUNC              O_TRUNC
 #define DFS_O_APPEND             O_APPEND
+
+#ifndef O_DIRECTORY
+#define O_DIRECTORY              0x0200000
+#endif
 #define DFS_O_DIRECTORY          O_DIRECTORY
 
 /* Seek flags */

components/libc/newlib/sys/fcntl.h

-#ifndef __RTT_FCNTL_H__
-#define __RTT_FCNTL_H__
-
-/* Operation flags */
-#define O_RDONLY        0x0000000
-#define O_WRONLY        0x0000001
-#define O_RDWR          0x0000002
-#define O_ACCMODE       0x0000003
-#define O_CREAT         0x0000100
-#define O_EXCL          0x0000200
-#define O_TRUNC         0x0001000
-#define O_APPEND        0x0002000
-#define O_DIRECTORY     0x0200000
-#define O_BINARY        0x0008000
-
-#endif