rename gprs_gsup_client.h to gsup_client.h

This is in preparation for moving gsup to libcommon, which is in turn
preparation for libvlr.

Related: OS#1592
Change-Id: I9c95d00f1a9420887a44c938b1d0ee3e20586f4c
diff --git a/openbsc/src/gprs/gprs_gsup_client.c b/openbsc/src/gprs/gprs_gsup_client.c
index cd94a8a..6195fa6 100644
--- a/openbsc/src/gprs/gprs_gsup_client.c
+++ b/openbsc/src/gprs/gprs_gsup_client.c
@@ -21,7 +21,7 @@
  *
  */
 
-#include <openbsc/gprs_gsup_client.h>
+#include <openbsc/gsup_client.h>
 
 #include <osmocom/abis/ipa.h>
 #include <osmocom/gsm/protocol/ipaccess.h>