MNCC_Types: Define '0' in various enums for unused value

it seems the decoder is using '0' in positions where we have
not defined any enum value for '0'.  Work around that.

Change-Id: I6bf0540f7ddd4dbe3b6c6ac06421a933126a7e17
diff --git a/library/MNCC_Types.ttcn b/library/MNCC_Types.ttcn
index 7bd47ee..f1d9e37 100644
--- a/library/MNCC_Types.ttcn
+++ b/library/MNCC_Types.ttcn
@@ -16,6 +16,7 @@
 
 /* GSM 04.08 Bearer Capability: Signalling access protocol */
 type enumerated GSM48_bcap_sig_access {
+	GSM48_BCAP_SA_NONE		(0),
 	GSM48_BCAP_SA_I440_I450 	(1),
 	GSM48_BCAP_SA_X21		(2),
 	GSM48_BCAP_SA_X28_DP_IN		(3),
@@ -26,6 +27,7 @@
 
 /* GSM 04.08 Bearer Capability: User Rate */
 type enumerated GSM48_bcap_user_rate {
+	GSM48_BCAP_UR_NONE		(0),
 	GSM48_BCAP_UR_300		(1),
 	GSM48_BCAP_UR_1200		(2),
 	GSM48_BCAP_UR_2400		(3),
@@ -46,6 +48,7 @@
 
 /* GSM 04.08 Bearer Capability: Intermediate Rate */
 type enumerated GSM48_bcap_interm_rate {
+	GSM48_BCAP_IR_NONE		(0),
 	GSM48_BCAP_IR_8k		(2),
 	GSM48_BCAP_IR_16k		(3)
 };