bootstrap: update tarfs driver with libfs support

sys/bootstrap/tar.h

@@ -1,6 +1,8 @@
 #ifndef TAR_H_
 #define TAR_H_
 
+#include <fs/context.h>
+#include <fs/status.h>
 #include <mango/types.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -42,4 +44,10 @@ extern int tar_header_decode(
 	const struct tar_bin_header *in,
 	struct tar_header *out);
 
+extern enum fs_status tar_mount(
+	struct fs_context *ctx,
+	void *arg,
+	enum fs_mount_flags flags,
+	struct fs_superblock **out);
+
 #endif