libxml2: Add fix of CVE-2014-3660.

* Add a patch which fixes CVE-2014-3660. Yocto master
  already have this patch. Dizzy brach was missing it.
  So added it in meta-metnor.
* JIRA SB-4116.

Signed-off-by: Noor Ahsan <noor_ahsan@mentor.com>