encoding: delete deprecated NInDatas and NOutDatas

Change-Id: Id112d298914232c1ce2f7bfda078633d3810bd99
Refs: #3955
diff --git a/src/encoding/tlv-nfd.hpp b/src/encoding/tlv-nfd.hpp
index 7462905..2799223 100644
--- a/src/encoding/tlv-nfd.hpp
+++ b/src/encoding/tlv-nfd.hpp
@@ -92,9 +92,6 @@
   Route    = 129
 };
 
-DEPRECATED() constexpr auto NInDatas = NInData;
-DEPRECATED() constexpr auto NOutDatas = NOutData;
-
 } // namespace nfd
 } // namespace tlv
 } // namespace ndn