libxml2: Add fix for CVE-2016-3709

Add below patch to fix CVE-2016-3709

CVE-2016-3709.patch
Link: https://github.com/GNOME/libxml2/commit/c1ba6f54d32b707ca6d91cb3257ce9de82876b6f



Signed-off-by: Pawan <Badganchi&lt;pawan.badganchi@kpit.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>