[ONOS-7281] Using slow protocol destination mac address (01:80:C2:00:00:0E), and supporting port description in ONOS LLDP

Change-Id: I98dfbad436da0b689a2ac89665ee3298c32b61e8
diff --git a/utils/misc/src/main/java/org/onlab/packet/LLDPTLV.java b/utils/misc/src/main/java/org/onlab/packet/LLDPTLV.java
index bfac8f0..62f2e7a 100644
--- a/utils/misc/src/main/java/org/onlab/packet/LLDPTLV.java
+++ b/utils/misc/src/main/java/org/onlab/packet/LLDPTLV.java
@@ -26,6 +26,9 @@
  *
  */
 public class LLDPTLV {
+
+    public static final int MAX_LENGTH = 0x1ff;
+
     protected byte type;
     protected short length;
     protected byte[] value;