bts: Pass defaults config name at construct time

It will be needed later at construction time when resolving the num of
trx.

Change-Id: I2c6a46ead14010f714897ea178917327215823e7
diff --git a/src/osmo_gsm_tester/bts_sysmo.py b/src/osmo_gsm_tester/bts_sysmo.py
index c9978e5..d0f6ff3 100644
--- a/src/osmo_gsm_tester/bts_sysmo.py
+++ b/src/osmo_gsm_tester/bts_sysmo.py
@@ -35,7 +35,7 @@
     BTS_SYSMO_CFG = 'osmo-bts-sysmo.cfg'
 
     def __init__(self, suite_run, conf):
-        super().__init__(suite_run, conf, SysmoBts.BTS_SYSMO_BIN)
+        super().__init__(suite_run, conf, SysmoBts.BTS_SYSMO_BIN, 'osmo_bts_sysmo')
         self.remote_user = 'root'
 
     def _direct_pcu_enabled(self):
@@ -103,7 +103,7 @@
         return os.path.join(SysmoBts.REMOTE_DIR, 'pcu_bts')
 
     def conf_for_bsc(self):
-        values = self.conf_for_bsc_osmo('osmo_bts_sysmo')
+        values = self.conf_for_bsc_prepare()
         self.dbg(conf=values)
         return values