TBF: add dedicated log categories

Previously all TBF-related events were logged as part of DRLCMAC which
is too broad to make it practically useful due to excessive amount of
log messages generated. Introduce dedicated log categories for
TBF-related events. Adjust test output as necessary.

Change-Id: I64d660e5971263d5c63d2ba95d50625c16a594aa
diff --git a/src/gprs_debug.cpp b/src/gprs_debug.cpp
index 283962f..f1ae6ad 100644
--- a/src/gprs_debug.cpp
+++ b/src/gprs_debug.cpp
@@ -32,6 +32,9 @@
 	{"DRLCMACUL", "\033[1;36m", "GPRS RLC/MAC layer Uplink (RLCMAC)", LOGL_NOTICE, 1},
 	{"DRLCMACSCHED", "\033[0;36m", "GPRS RLC/MAC layer Scheduling (RLCMAC)", LOGL_NOTICE, 1},
 	{"DRLCMACMEAS", "\033[1;31m", "GPRS RLC/MAC layer Measurements (RLCMAC)", LOGL_INFO, 1},
+	{"DTBF","\033[1;34m", "Temporary Block Flow (TBF)", LOGL_INFO , 1},
+	{"DTBFDL","\033[1;34m", "Temporary Block Flow (TBF) Downlink", LOGL_INFO , 1},
+	{"DTBFUL","\033[1;34m", "Temporary Block Flow (TBF) Uplink", 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},