Creating a p4runtime default driver to avoid code duplication between bmv2 and barefoot drivers

Change-Id: Id7f16a284c65278ec1a9ec682da01ddf020343c8
diff --git a/modules.defs b/modules.defs
index fa8a16d..fbb83b9 100644
--- a/modules.defs
+++ b/modules.defs
@@ -106,6 +106,7 @@
     '//drivers/oplink:onos-drivers-oplink-oar',
     '//drivers/bmv2:onos-drivers-bmv2-oar',
     '//drivers/hp:onos-drivers-hp-oar',
+    '//drivers/p4runtime:onos-drivers-p4runtime-oar',
 ]
 
 ONOS_PROVIDERS = [