[ndnSIM] lp, face: Add lp::HopCountTagField

Change-Id: I2c25bcf29f3928049d1040a3e421e1c7151b3ba2
diff --git a/src/lp/tlv.hpp b/src/lp/tlv.hpp
index 1b409ca..bb88967 100644
--- a/src/lp/tlv.hpp
+++ b/src/lp/tlv.hpp
@@ -35,6 +35,7 @@
   Sequence = 81,
   FragIndex = 82,
   FragCount = 83,
+  HopCountTag = 84,
   Nack = 800,
   NackReason = 801,
   NextHopFaceId = 816,