gcc:
 * enable TLS for firmwares using NPTL enabled uClibc
 * fixes build problem reported [http://freetz.org/ticket/1939#comment:40 in this comment]
 * refs #1939, refs r10524


git-svn-id: file:///var/svn/freetz/trunk@10531 149334a1-2f27-0410-a3b9-fc62619ac1e6