ep: move endpoint struct and define to mgcp_ep.h

The endpoint and the define that computes the endpoint number is
defined in mgcp_internal.h. Since we have a dedicated module for
endpoint related code it makes sense to move the endpoint related
parts there.

- move struct mgcp_endpoint to mgcp_ep.h

- move #define ENDPOINT_NUMBER(endp) to mgcp_ep.h

Change-Id: Ibae55e1859bd41e2d1918eda433418b4bf8365fe
diff --git a/src/libosmo-mgcp/mgcp_ep.c b/src/libosmo-mgcp/mgcp_ep.c
index 68e36da..0b67ec8 100644
--- a/src/libosmo-mgcp/mgcp_ep.c
+++ b/src/libosmo-mgcp/mgcp_ep.c
@@ -21,8 +21,8 @@
  *
  */
 
-#include <osmocom/mgcp/mgcp_ep.h>
 #include <osmocom/mgcp/mgcp_internal.h>
+#include <osmocom/mgcp/mgcp_ep.h>
 
 /* Endpoint typeset definition */
 const struct mgcp_endpoint_typeset ep_typeset = {