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/mncc_builtin.c b/src/libmsc/mncc_builtin.c
index c1debc5..6474201 100644
--- a/src/libmsc/mncc_builtin.c
+++ b/src/libmsc/mncc_builtin.c
@@ -88,6 +88,8 @@
 	/* we currently only do speech and CSD */
 	switch (setup->bearer_cap.transfer) {
 	case GSM_MNCC_BCAP_SPEECH:
+	case GSM_MNCC_BCAP_AUDIO:
+	case GSM_MNCC_BCAP_FAX_G3:
 	case GSM_MNCC_BCAP_UNR_DIG:
 		break;
 	default: