Move headers under the hf directory.

This helps distinguish local headers from the more official headers.

Change-Id: I535c1b44081b9d60ba63666cd1ad514aaaf2c68d
diff --git a/inc/hf/cpio.h b/inc/hf/cpio.h
new file mode 100644
index 0000000..de33ba6
--- /dev/null
+++ b/inc/hf/cpio.h
@@ -0,0 +1,12 @@
+#ifndef _CPIO_H
+#define _CPIO_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "hf/memiter.h"
+
+bool cpio_next(struct memiter *iter, const char **name, const void **contents,
+	       size_t *size);
+
+#endif /* _CPIO_H */