library/RSL_Types: RSL_SpeechAlgo: support CSD

Prepare to test CSD in BSC_Tests.ttcn. After sending a BSSAP assignment
request to the BSC with channel type data, the BSC will send a channel
activation via RSL to the BTS (which is emulated by the testsuite).

Without CSD support in the RSL template, the testsuite is unable to
decode the message, prints "Data remained at the end of the stream
after successful decoding" and the test fails.

Related: OS#4393
Change-Id: Ief2d95c7e9d71afb26fa74da755294226c8e158d
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index b9182e3..31b733f 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -4342,30 +4342,30 @@
 			dtx_u := ?,
 			spd_ind := RSL_SPDI_SPEECH,
 			ch_rate_type := -,
-			coding_alg_rate := -
+			u := { speech := - }
 		}
 	}
 
 	select (a_elem.codecType) {
 	case (GSM_FR) {
 		mode_ie.chan_mode.ch_rate_type := RSL_CHRT_TCH_F;
-		mode_ie.chan_mode.coding_alg_rate := RSL_CMOD_SP_GSM1;
+		mode_ie.chan_mode.u.speech := RSL_CMOD_SP_GSM1;
 	}
 	case (GSM_HR) {
 		mode_ie.chan_mode.ch_rate_type := RSL_CHRT_TCH_H;
-		mode_ie.chan_mode.coding_alg_rate := RSL_CMOD_SP_GSM1;
+		mode_ie.chan_mode.u.speech := RSL_CMOD_SP_GSM1;
 	}
 	case (GSM_EFR) {
 		mode_ie.chan_mode.ch_rate_type := RSL_CHRT_TCH_F;
-		mode_ie.chan_mode.coding_alg_rate := RSL_CMOD_SP_GSM2;
+		mode_ie.chan_mode.u.speech := RSL_CMOD_SP_GSM2;
 	}
 	case (FR_AMR) {
 		mode_ie.chan_mode.ch_rate_type := RSL_CHRT_TCH_F;
-		mode_ie.chan_mode.coding_alg_rate := RSL_CMOD_SP_GSM3;
+		mode_ie.chan_mode.u.speech := RSL_CMOD_SP_GSM3;
 	}
 	case (HR_AMR) {
 		mode_ie.chan_mode.ch_rate_type := RSL_CHRT_TCH_H;
-		mode_ie.chan_mode.coding_alg_rate := RSL_CMOD_SP_GSM3;
+		mode_ie.chan_mode.u.speech := RSL_CMOD_SP_GSM3;
 	}
 	}
 	return mode_ie;