Add udp.api.h to vnet.am

Change-Id: I77c1da7ba3770637a3414226f7ade229b8b0d216
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet.am b/src/vnet.am
index 3204a5b..aea5b21 100644
--- a/src/vnet.am
+++ b/src/vnet.am
@@ -526,7 +526,8 @@
 nobase_include_HEADERS +=			\
   vnet/udp/udp_error.def                       	\
   vnet/udp/udp.h                               	\
-  vnet/udp/udp_packet.h
+  vnet/udp/udp_packet.h				\
+  vnet/udp/udp.api.h
 
 API_FILES += vnet/udp/udp.api