feeds: include NSS packages

NSS packages required for wired networking and NSS ofloading are located
in a external package feed.

Include the feed by default in order to provide wired networking on
IPQ807x.

Signed-off-by: Robert Marko <robimarko@gmail.com>

feeds.conf.default

@@ -2,6 +2,7 @@ src-git-full packages https://git.openwrt.org/feed/packages.git
 src-git-full luci https://git.openwrt.org/project/luci.git
 src-git-full routing https://git.openwrt.org/feed/routing.git
 src-git-full telephony https://git.openwrt.org/feed/telephony.git
+src-git-full nss_packages https://github.com/robimarko/nss-packages.git
 #src-git-full video https://github.com/openwrt/video.git
 #src-git-full targets https://github.com/openwrt/targets.git
 #src-git-full oldpackages http://git.openwrt.org/packages.git