Added "drivers" to cells that defined ONOS_APPS.

Change-Id: I8e7cbea037ea09504662fb17ef328b547d21050a
diff --git a/tools/test/cells/sdnip-pmox b/tools/test/cells/sdnip-pmox
index 0329616..e95b7e7 100644
--- a/tools/test/cells/sdnip-pmox
+++ b/tools/test/cells/sdnip-pmox
@@ -5,4 +5,4 @@
 export OC2="10.128.4.66"
 export OC3="10.128.4.67"
 
-export ONOS_APPS="openflow,fwd,proxyarp,mobility,config,sdnip"
+export ONOS_APPS="drivers,openflow,fwd,proxyarp,mobility,config,sdnip"