[ipa] Change names of RTP methods to follow MGCP naming

IPA is naming these functions CRCX, MDCX, DLCX to follow
the naming of the MediaGatewayControlProtocol. Change the
code to go from BIND to CRCX (create connection) and from
CONNECT to MDCX (modify connection).

Connect indicates that it is only possible to call it once
while it is possible to call it more than once to modify
the audio parmaters and such. So the IPA terminology is
making a bit more sense here (now that we know it).
diff --git a/openbsc/include/openbsc/abis_rsl.h b/openbsc/include/openbsc/abis_rsl.h
index 1ffea3f..a911be3 100644
--- a/openbsc/include/openbsc/abis_rsl.h
+++ b/openbsc/include/openbsc/abis_rsl.h
@@ -142,16 +142,16 @@
 	RSL_MT_IPAC_DISC_MUX		= 0x56,
 	RSL_MT_IPAC_DISC_MUX_ACK,
 	RSL_MT_IPAC_DISC_MUX_NACK,
-	RSL_MT_IPAC_BIND		= 0x70,		/* Bind to local BTS RTP port */
-	RSL_MT_IPAC_BIND_ACK,
-	RSL_MT_IPAC_BIND_NACK,
-	RSL_MT_IPAC_CONNECT		= 0x73,
-	RSL_MT_IPAC_CONNECT_ACK,
-	RSL_MT_IPAC_CONNECT_NACK,
-	RSL_MT_IPAC_DISCONNECT_IND	= 0x76,
-	RSL_MT_IPAC_DISCONNECT		= 0x77,
-	RSL_MT_IPAC_DISCONNECT_ACK,
-	RSL_MT_IPAC_DISCONNECT_NACK,
+	RSL_MT_IPAC_CRCX		= 0x70,		/* Bind to local BTS RTP port */
+	RSL_MT_IPAC_CRCX_ACK,
+	RSL_MT_IPAC_CRCX_NACK,
+	RSL_MT_IPAC_MDCX		= 0x73,
+	RSL_MT_IPAC_MDCX_ACK,
+	RSL_MT_IPAC_MDCX_NACK,
+	RSL_MT_IPAC_DLCX_IND		= 0x76,
+	RSL_MT_IPAC_DLCX		= 0x77,
+	RSL_MT_IPAC_DLCX_ACK,
+	RSL_MT_IPAC_DLCX_NACK,
 };
 
 /* Siemens vendor-specific */
@@ -535,10 +535,10 @@
 int rsl_siemens_mrpci(struct gsm_lchan *lchan, struct rsl_mrpci *mrpci);
 
 /* ip.access specfic RSL extensions */
-int rsl_ipacc_bind(struct gsm_lchan *lchan);
-int rsl_ipacc_connect(struct gsm_lchan *lchan, u_int32_t ip,
-		      u_int16_t port, u_int16_t conn_id,
-		      u_int8_t rtp_payload2);
+int rsl_ipacc_crcx(struct gsm_lchan *lchan);
+int rsl_ipacc_mdcx(struct gsm_lchan *lchan, u_int32_t ip,
+		   u_int16_t port, u_int16_t conn_id,
+		   u_int8_t rtp_payload2);
 int rsl_ipacc_pdch_activate(struct gsm_lchan *lchan);
 
 int abis_rsl_rcvmsg(struct msgb *msg);