libc: Import from TF-A

Based on arm-trusted-firware commit 873e394b3bf93214a441f9f98237b58fbbea55aa

Change-Id: I510e092f2b9ff333e9461bdde8d80ed1fab1460c
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
diff --git a/include/lib/libc/stdbool.h b/include/lib/libc/stdbool.h
new file mode 100644
index 0000000..e39aef7
--- /dev/null
+++ b/include/lib/libc/stdbool.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef STDBOOL_H
+#define STDBOOL_H
+
+#define bool	_Bool
+
+#define true	1
+#define false	0
+
+#define __bool_true_false_are_defined	1
+
+#endif /* STDBOOL_H */