Move mlnx agent to be under ml2/drivers/mlnx

* move the mlnx agent to be under ml2/drivers/mlnx
* update the main entry point to be under cmd
* remove unused vnic_type parameter in agent config

Partially-implements: blueprint core-vendor-decomposition

Change-Id: Ibbb99de3124d5d81bbccbc06b33ce32b19c1daef

neutron/cmd/eventlet/plugins/mlnx_neutron_agent.py

@@ -0,0 +1,19 @@
+#    Copyright 2015 Mellanox Technologies, Ltd
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from neutron.plugins.ml2.drivers.mlnx.agent import eswitch_neutron_agent
+
+
+def main():
+    eswitch_neutron_agent.main()