Added dummy mellanox driver

Change-Id: I0dc9643709ca1b691f4ac153982be56359544807
diff --git a/mwc.defs b/mwc.defs
index a7312a7..461192e 100644
--- a/mwc.defs
+++ b/mwc.defs
@@ -4,6 +4,7 @@
     '//pipelines/fabric-pro:onos-pipelines-fabric-pro-oar',
     '//drivers/barefoot-pro:onos-drivers-barefoot-pro-oar',
     '//drivers/cavium-pro:onos-drivers-cavium-pro-oar',
+    '//drivers/mellanox-pro:onos-drivers-mellanox-pro-oar',
 ]
 
 APPS = APPS + MWC_APPS