[ONOS-7051] Support for P4Runtime meters

Change-Id: Id71374af65aeb84b71636b4ec230dc6001a77a8b
diff --git a/pipelines/basic/src/main/resources/include/custom_headers.p4 b/pipelines/basic/src/main/resources/include/custom_headers.p4
index 035e322..a57b076 100644
--- a/pipelines/basic/src/main/resources/include/custom_headers.p4
+++ b/pipelines/basic/src/main/resources/include/custom_headers.p4
@@ -29,6 +29,7 @@
     bit<16>       l4_src_port;
     bit<16>       l4_dst_port;
     next_hop_id_t next_hop_id;
+    bit<32>       meter_tag;
 }
 
-#endif
\ No newline at end of file
+#endif