cosmetic: rename mgcp_ep.c/h to mgcp_endp.c/h

The short term of endpoint has always been "endp" througout the whole
project and not "ep".

- rename mcgp_ep.c to mgcp_endp.c

- rename mgcp_ep.h to mgcp_endp.h

Change-Id: Id52047bb2d0407655ac272c858ed3412b8ae9e6d
diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index 4d39bda..38a0a46 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -25,7 +25,7 @@
 #include <osmocom/mgcp/mgcp_internal.h>
 #include <osmocom/mgcp/mgcp_stat.h>
 #include <osmocom/mgcp/mgcp_msg.h>
-#include <osmocom/mgcp/mgcp_ep.h>
+#include <osmocom/mgcp/mgcp_endp.h>
 
 #include <osmocom/core/application.h>
 #include <osmocom/core/talloc.h>