doc: Always annotate codec port types in case of IPL4/UD ports

Change-Id: Icee6eeb4a526ff5cbeb8b01df8149c488875455e
diff --git a/doc/bts_tests.dot b/doc/bts_tests.dot
index 8cbb5b1..3fd9471 100644
--- a/doc/bts_tests.dot
+++ b/doc/bts_tests.dot
@@ -39,7 +39,7 @@
 		shape = "record"
 		label = "<f0> IPA_Emulation_CT | <MTP3_SP_PORT> MTP3_SP_PORT | <IPA_MGCP_PORT> IPA_MGCP_PORT | <IPA_RSL_PORT> IPA_RSL_PORT | <IPA_OML_PORT> IPA_OML_PORT | <IPA_CTRL_PORT> IPA_CTRL_PORT | <IPA_GSUP_PORT> IPA_GSUP_PORT | <IPA_RSPRO_PORT> IPA_RSPRO_PORT | <IPA_OSMO_PCU_PORT> IPA_OSMO_PCU_PORT | <IPA_SP_PORT> IPA_SP_PORT | <IPA_PORT> IPA_PORT"
 	];
-	"IPA_Emulation_CT":IPA_PORT -> "system":IPL4
+	"IPA_Emulation_CT":IPA_PORT -> "system":IPL4 [label="IPA_CODEC_PT"]
 
 
 	"system" [