[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/drivers/optical/src/main/java/org/onosproject/drivers/optical/OpticalDriversLoader.java b/drivers/optical/src/main/java/org/onosproject/drivers/optical/OpticalDriversLoader.java
new file mode 100644
index 0000000..4b84302
--- /dev/null
+++ b/drivers/optical/src/main/java/org/onosproject/drivers/optical/OpticalDriversLoader.java
@@ -0,0 +1,37 @@
+package org.onosproject.drivers.optical;
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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.
+ */
+
+
+
+import org.apache.felix.scr.annotations.Component;
+import org.onosproject.net.driver.AbstractDriverLoader;
+import org.onosproject.net.optical.OpticalDevice;
+
+/**
+ * Loader for other optical device drivers.
+ */
+@Component(immediate = true)
+public class OpticalDriversLoader extends AbstractDriverLoader {
+
+    // OSGI: help bundle plugin discover runtime package dependency.
+    @SuppressWarnings("unused")
+    private OpticalDevice optical;
+
+    public OpticalDriversLoader() {
+        super("/optical-drivers.xml");
+    }
+}