cosmetic: rename bsc_api.h to gsm_08_08.h

See also I91922f557072d0fb8cfe213a8a7b50f3bb23dea0, which renames
osmo_bsc_api.c to gsm_08_08.c.

Change-Id: I7179eb27183ee213f8fc8d548895b67aa43dc6a2
diff --git a/tests/handover/handover_test.c b/tests/handover/handover_test.c
index a962777..76e5fe1 100644
--- a/tests/handover/handover_test.c
+++ b/tests/handover/handover_test.c
@@ -40,7 +40,7 @@
 #include <osmocom/bsc/handover_cfg.h>
 #include <osmocom/bsc/handover_decision_2.h>
 #include <osmocom/bsc/bss.h>
-#include <osmocom/bsc/bsc_api.h>
+#include <osmocom/bsc/gsm_08_08.h>
 #include <osmocom/bsc/osmo_bsc.h>
 #include <osmocom/bsc/bsc_subscr_conn_fsm.h>
 #include <osmocom/bsc/timeslot_fsm.h>