osmo-trx: Enable multi_arfcn for B200 and only in multiTRX setup

Change-Id: I6a29e1813f0603b00b49b7b7c805be23a72cf0e3

example/resources.conf.prod

@@ -30,6 +30,7 @@ bts:
     remote_user: jenkins
     trx_ip: 10.42.42.230
     clock_reference: external
+    multi_arfcn: true
 
 - label: sysmoCell 5000
   type: osmo-bts-trx

example/resources.conf.rnd

@@ -28,6 +28,7 @@ bts:
     type: uhd
     launch_trx: true
     clock_reference: external
+    multi_arfcn: true
     remote_user: jenkins
     trx_ip: 127.0.0.1
   ciphers: [a5_0, a5_1]

src/osmo_gsm_tester/bts_osmotrx.py

@@ -179,7 +179,12 @@ class OsmoTrx(log.Origin, metaclass=ABCMeta):
         self.dbg(config_file=self.config_file)
 
         values = self.conf
-        multi_arfcn_bool = util.str2bool(values.get('osmo_trx', {}).get('multi_arfcn', False))
+
+        # we don't need to enable multi-arfcn for single channel
+        if len(values.get('osmo_trx', {}).get('channels', [])) > 1:
+            multi_arfcn_bool = util.str2bool(values.get('osmo_trx', {}).get('multi_arfcn', False))
+        else:
+            multi_arfcn_bool = False
         config.overlay(values, { 'osmo_trx': { 'multi_arfcn': multi_arfcn_bool } })
 
         self.dbg('OSMO-TRX CONFIG:\n' + pprint.pformat(values))