meta-google: gbmc-ncsi-config: Add unreachable bridge route

We don't want traffic being routed back out of the BMC when it is
destined for the BMC network. It's nice that unrecognized routes return
an obvious unreachable error to the end user.

Change-Id: If261faf7b8f2416ee9a802f85db17ed62946625d
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
index 949f04f..961da50 100644
--- a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
+++ b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
@@ -55,6 +55,10 @@
 [IPv6RoutePrefix]
 Route=$ncsi_pfx/80
 LifetimeSec=60
+[Route]
+Destination=$stateless_pfx/72
+Type=unreachable
+Metric=1024
 EOF
     contents+="$here"$'\n'
   fi