as discussed with wbx@ some 2-3 weeks ago, change the BR2_ prefix to FWRT_
tested with a standard build (only the squashfs image since the jffs2 didn't get built)
git-svn-id: svn://www.freewrt.org/trunk/freewrt@360 afb5a338-a214-0410-bd46-81f09a774fd1