[ONOS-4588] Separate optical driver from "default" driver bundle

Note: If you're using optical devices currently in "default" driver bundle,
(LINC-OE, Calient fiber switch, ECI devices, OpLink ROADM)

you'll need to load the driver/app "drivers.optical" in adition to default drivers

e.g.,
a) Add to cell definition
 export ONOS_APPS=${ONOS_APPS},drivers.optical

b) Activate after starting ONOS
 onos> app activate org.onosproject.drivers.optical

Change-Id: I126c09bebc816d11b4700a80e7a36a8e6c3e1b49
diff --git a/BUCK b/BUCK
index 4a103fe..ac4c194 100644
--- a/BUCK
+++ b/BUCK
@@ -54,6 +54,7 @@
     '//drivers/lumentum:onos-drivers-lumentum-oar',
     '//drivers/netconf:onos-drivers-netconf-oar',
     '//drivers/ovsdb:onos-drivers-ovsdb-oar',
+    '//drivers/optical:onos-drivers-optical-oar',
 
     '//providers/netconf/device:onos-providers-netconf-device',
     '//providers/openflow/device:onos-providers-openflow-device',