LFS nits

src/lfs.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#if MG_ENABLE_LFS
+#include <fcntl.h>
+#include <littlefs/lfs.h>
+
+#ifndef DT_DIR
+#define DT_DIR 4
+#endif
+#ifndef DT_REG
+#define DT_REG 8
+#endif
+
+struct dirent {
+  char d_name[LFS_NAME_MAX + 1];
+  unsigned char d_type;
+};
+
+typedef struct mg_lfs_fd  DIR;
+#endif