gsup: Decode/Encode the hlr-Number in the GSUP message

Implement it similar to the msisdn_enc/msisdn_enc_len and
extend the testcase to include it as well.
diff --git a/openbsc/src/gprs/gprs_gsup_messages.c b/openbsc/src/gprs/gprs_gsup_messages.c
index cb14fa1..bdcff5f 100644
--- a/openbsc/src/gprs/gprs_gsup_messages.c
+++ b/openbsc/src/gprs/gprs_gsup_messages.c
@@ -303,6 +303,11 @@
 			gsup_msg->msisdn_enc_len = value_len;
 			break;
 
+		case GPRS_GSUP_HLR_NUMBER_IE:
+			gsup_msg->hlr_enc = value;
+			gsup_msg->hlr_enc_len = value_len;
+			break;
+
 		default:
 			LOGP(DGPRS, LOGL_NOTICE,
 			     "GSUP IE type %d unknown\n", iei);
@@ -394,6 +399,9 @@
 	if (gsup_msg->msisdn_enc)
 		msgb_tlv_put(msg, GPRS_GSUP_MSISDN_IE,
 				gsup_msg->msisdn_enc_len, gsup_msg->msisdn_enc);
+	if (gsup_msg->hlr_enc)
+		msgb_tlv_put(msg, GPRS_GSUP_HLR_NUMBER_IE,
+				gsup_msg->hlr_enc_len, gsup_msg->hlr_enc);
 
 	if ((u8 = gsup_msg->cause))
 		msgb_tlv_put(msg, GPRS_GSUP_CAUSE_IE, sizeof(u8), &u8);