ip: Use .api declarative counters for ICMP.

Type: improvement

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I3d36faa60075658fd59eb5bbe16efcb48664691b
diff --git a/src/vnet/l2/l2_arp_term.c b/src/vnet/l2/l2_arp_term.c
index 17c8b1d..d073432 100644
--- a/src/vnet/l2/l2_arp_term.c
+++ b/src/vnet/l2/l2_arp_term.c
@@ -25,6 +25,7 @@
 #include <vnet/ip/ip6_packet.h>
 #include <vnet/ip/icmp6.h>
 #include <vnet/ip/ip6.h>
+#include <vnet/ip/ip.api_enum.h>
 #include <vnet/ip/format.h>
 #include <vnet/ethernet/arp_packet.h>