libmsc: add 3k1_AUDIO and FAX_G3 bearer cap

Bearer capability 3k1_AUDIO and FAX_G3 are only important
for the interworking function, the MSC should handle
these calls the same as CSD calls with unrestricted digital
bearer capability.

Change-Id: I198aa867a8f236b8ddd05d3b2356f64b876fd4c1
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 1e2c5af..31fcb23 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -825,6 +825,8 @@
 			LOG_TRANS(trans, LOGL_INFO,
 				  "Got no information of remote audio codecs: neither SDP nor Bearer Capability. Trying anyway.\n");
 		break;
+	case GSM48_BCAP_ITCAP_3k1_AUDIO:
+	case GSM48_BCAP_ITCAP_FAX_G3:
 	case GSM48_BCAP_ITCAP_UNR_DIG_INF:
 		if (setup->fields & MNCC_F_BEARER_CAP) {
 			trans->cc.remote = (struct sdp_msg){};
@@ -878,6 +880,8 @@
 			return rc;
 		}
 		break;
+	case GSM48_BCAP_ITCAP_3k1_AUDIO:
+	case GSM48_BCAP_ITCAP_FAX_G3:
 	case GSM48_BCAP_ITCAP_UNR_DIG_INF:
 		if (csd_bs_list_to_bearer_cap(&bearer_cap, &trans->cc.local.bearer_services) == 0) {
 			LOG_TRANS(trans, LOGL_ERROR, "Error composing Bearer Capability for CC Setup\n");