[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/pom.xml b/drivers/pom.xml
index 6349ed9..99db6e1 100644
--- a/drivers/pom.xml
+++ b/drivers/pom.xml
@@ -43,6 +43,7 @@
         <module>bti</module>
         <module>bmv2</module>
         <module>corsa</module>
+        <module>optical</module>
     </modules>
 
     <!--<properties>