Configure the ovs switch/bridge based on the olt host port configuration in olt_config.json
Also account for this fact in the tests relying on ovsbr0 if ovs was running locally.
Change eval script hacks for ovsbr0 as it isn't required with the new changes to pick up switch from the config file.

Change-Id: I1b85eeea6bce822352711eeaaab5e5a01bc3938b
diff --git a/src/test/utils/OnosCtrl.py b/src/test/utils/OnosCtrl.py
index 09cbeee..22afa56 100644
--- a/src/test/utils/OnosCtrl.py
+++ b/src/test/utils/OnosCtrl.py
@@ -19,7 +19,9 @@
 from OltConfig import OltConfig
 import fcntl, socket, struct
 
-def get_mac(iface = 'ovsbr0', pad = 4):
+def get_mac(iface = None, pad = 4):
+    if iface is None:
+        iface = os.getenv('TEST_SWITCH', 'ovsbr0')
     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     try:
         info = fcntl.ioctl(s.fileno(), 0x8927, struct.pack('256s', bytes(iface[:15])))
@@ -78,7 +80,7 @@
     def get_device_id(cls):
         '''If running under olt, we get the first switch connected to onos'''
         olt = OltConfig()
-        did = 'of:' + get_mac('ovsbr0')
+        did = 'of:' + get_mac()
         if olt.on_olt():
             devices = cls.get_devices()
             if devices: