[source] vti: add empty install rules for vtiv4 & vtiv6

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/f67867adb054e16a73c5f644e5bdf77e64eaddcf

commit f67867adb054e16a73c5f644e5bdf77e64eaddcf
Author: Alexandru Ardelean <ardeleanalex at gmail.com>
AuthorDate: Tue Nov 8 16:28:43 2016 +0200

    vti: add empty install rules for vtiv4 & vtiv6
    
    Same as for grev4 & grev6
    
    Signed-off-by: Alexandru Ardelean <ardeleanalex at gmail.com>
---
 package/network/config/vti/Makefile | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/package/network/config/vti/Makefile b/package/network/config/vti/Makefile
index 7cf0ee9..bda2a9a 100644
--- a/package/network/config/vti/Makefile
+++ b/package/network/config/vti/Makefile
@@ -60,6 +60,14 @@ define Package/vti/install
 	$(INSTALL_BIN) ./files/vti.sh $(1)/lib/netifd/proto/vti.sh
 endef
 
+define Package/vtiv4/install
+	:
+endef
+
+define Package/vtiv6/install
+	:
+endef
+
 $(eval $(call BuildPackage,vti))
 $(eval $(call BuildPackage,vtiv4))
 $(eval $(call BuildPackage,vtiv6))