get rid of mgcp_internal.h

The file mgcp_internal.h still contains mostly definitions and types
that are relevant for mgcp_network.c and mgcp_protocol.c. Lets give
the network and protocol module its own header files, also move stuff
that does not relate to protocol and network to the appropiate places.

Change-Id: I837eaad771ed7252304db4a81c37953b70766fff
diff --git a/src/libosmo-mgcp/mgcp_stat.c b/src/libosmo-mgcp/mgcp_stat.c
index 3685cfe..2e74238 100644
--- a/src/libosmo-mgcp/mgcp_stat.c
+++ b/src/libosmo-mgcp/mgcp_stat.c
@@ -22,10 +22,12 @@
  *
  */
 
-#include <osmocom/mgcp/mgcp_stat.h>
-#include <osmocom/mgcp/mgcp_endp.h>
 #include <limits.h>
 #include <inttypes.h>
+#include <osmocom/mgcp/mgcp_protocol.h>
+#include <osmocom/mgcp/mgcp_conn.h>
+#include <osmocom/mgcp/mgcp_stat.h>
+#include <osmocom/mgcp/mgcp_endp.h>
 
 /* Helper function for mgcp_format_stats_rtp() to calculate packet loss */
 void calc_loss(struct mgcp_conn_rtp *conn, uint32_t *expected, int *loss)