IPSEC: header exports

Change-Id: I7d48a4e236c6e7b11b0c9750a30fb68e829d64a5
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 0cf31ff..2548ed4 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -21,6 +21,7 @@
 
 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ipsec_io.h>
 
 #define foreach_esp_decrypt_next                \
 _(DROP, "error-drop")                           \