encoding: delete deprecated namespace ndn::Tlv

refs #2079

Change-Id: Ia465eb0aeb8084aac035d2d20475daf838acb5ef
diff --git a/src/encoding/tlv.hpp b/src/encoding/tlv.hpp
index 7f8169d..0fb4704 100644
--- a/src/encoding/tlv.hpp
+++ b/src/encoding/tlv.hpp
@@ -540,9 +540,6 @@
 
 } // namespace tlv
 
-/// @deprecated use namespace tlv instead
-namespace Tlv = tlv;
-
 } // namespace ndn
 
 #endif // NDN_ENCODING_TLV_HPP