feeds: add openwrt-routing feed and drop bmx6 feed which got merged into openwrt-routing

SVN-Revision: 36368

feeds.conf.default

 src-svn packages svn://svn.openwrt.org/openwrt/packages
 src-svn xwrt http://x-wrt.googlecode.com/svn/trunk/package
 src-git luci git://nbd.name/luci.git
-src-git bmx6 git://bmx6.net/bmx6/bmx6-openwrt.git
+src-git openwrt-routing git://github.com/openwrt-routing/packages.git
 #src-svn phone svn://svn.openwrt.org/openwrt/feeds/phone
 #src-svn efl svn://svn.openwrt.org/openwrt/feeds/efl
 #src-svn xorg svn://svn.openwrt.org/openwrt/feeds/xorg