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/limits.h b/include/lib/libc/limits.h
new file mode 100644
index 0000000..41bb658
--- /dev/null
+++ b/include/lib/libc/limits.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2012-2017 Roberto E. Vargas Caballero
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
+
+#ifndef LIMITS_H
+#define LIMITS_H
+
+#include <limits_.h>
+
+#define CHAR_BIT   8
+#define MB_LEN_MAX 1
+
+#endif /* LIMITS_H */