ip.access: Keep a full copy of local and remote IP/PORT in lchan

Keeping all parameters for each RTP connection in the abis_ip member of
lchan will help us with actual TCH handover later on.
diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index f9b0b63..67465e4 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -200,9 +200,12 @@
 
 	struct {
 		u_int32_t bound_ip;
+		u_int32_t connect_ip;
 		u_int16_t bound_port;
-		u_int8_t rtp_payload2;
+		u_int16_t connect_port;
 		u_int16_t conn_id;
+		u_int8_t rtp_payload2;
+		u_int8_t speech_mode;
 		struct rtp_socket *rtp_socket;
 	} abis_ip;
 };