[fix] sal build error.

components/libc/compilers/common/extension/sys/stat.h

@@ -55,7 +55,7 @@ extern "C" {
 
 struct stat
 {
-    struct rt_device *st_dev;
+    dev_t st_dev;
     uint16_t  st_ino;
     uint16_t  st_mode;
     uint16_t  st_nlink;

components/net/sal/src/sal_socket.c

@@ -11,6 +11,8 @@
 
 #include <rtthread.h>
 #include <rthw.h>
+
+#include <string.h>
 #include <sys/time.h>
 #include <sys/ioctl.h>