codec_mapping: add clearmode

Related: OS#4394
Change-Id: Ieeaca6a00dc332424d443e44251f3219245511db
diff --git a/src/libmsc/codec_mapping.c b/src/libmsc/codec_mapping.c
index 81ab79c..b58efd9 100644
--- a/src/libmsc/codec_mapping.c
+++ b/src/libmsc/codec_mapping.c
@@ -203,6 +203,14 @@
 		},
 		.mgcp = CODEC_IUFP,
 	},
+	{
+		.sdp = {
+			.payload_type = 120,
+			.subtype_name = "CLEARMODE",
+			.rate = 8000,
+		},
+		.mgcp = CODEC_CLEARMODE,
+	},
 };
 
 #define foreach_codec_mapping(CODEC_MAPPING) \