VOL-34 Add group printing at CLI

Change-Id: I4e8e55ffd397c3d1486dc2807e92dd87eea9856e
diff --git a/cli/logical_device.py b/cli/logical_device.py
index c1a9479..0545c69 100644
--- a/cli/logical_device.py
+++ b/cli/logical_device.py
@@ -23,7 +23,7 @@
 
 from cli.table import print_pb_as_table, print_pb_list_as_table
 from cli.utils import pb2dict
-from cli.utils import print_flows
+from cli.utils import print_flows, print_groups
 from voltha.protos import third_party
 from google.protobuf.empty_pb2 import Empty
 
@@ -88,6 +88,16 @@
             groups=logical_device['flow_groups']['items']
         )
 
+    def do_groups(self, _):
+        """Show flow group table for logical device"""
+        logical_device = pb2dict(self.get_logical_device(-1))
+        print_groups(
+            'Logical Device',
+            self.logical_device_id,
+            type='n/a',
+            groups=logical_device['flow_groups']['items']
+        )
+
     def do_devices(self, line):
         """List devices that belong to this logical device"""
         logical_device = self.get_logical_device()