ns: Add logging support

Currently there is not support for Network Service (NS) logging.

This commit adds the missing definitions and sets the default level
to INFO. Further configuration can now be done with the 'logging
level ns' VTY command.

Sponsored-by: On-Waves ehf
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 19895ad..865081b 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -654,6 +654,7 @@
         {"DRLCMACUL", "\033[1;36m", "GPRS RLC/MAC layer Uplink (RLCMAC)", LOGL_DEBUG, 1},
         {"DRLCMACSCHED", "\033[0;36m", "GPRS RLC/MAC layer Scheduling (RLCMAC)", LOGL_DEBUG, 1},
         {"DRLCMACMEAS", "\033[1;31m", "GPRS RLC/MAC layer Measurements (RLCMAC)", LOGL_INFO, 1},
+        {"DNS","\033[1;34m", "GPRS Network Service Protocol (NS)", LOGL_INFO , 1},
         {"DBSSGP","\033[1;34m", "GPRS BSS Gateway Protocol (BSSGP)", LOGL_INFO , 1},
         {"DPCU", "\033[1;35m", "GPRS Packet Control Unit (PCU)", LOGL_NOTICE, 1},
 };