A new RestSB driver named TapiDeviceDescriptionDiscovery.java is included within onos-odtn drivers subproject. This driver accounts for the deviceDescriptionDiscovery behavior.

Removed unneeded imports and star imports, added explicit imports.
Removed logs or changed them to debug level.
Removed stalled references.
Changed pakage to org.onosproject.drivers.odtn.tapi.
Changed the class of port number to ONOS PortNumber.
Changed the store of mapping information between TAPI SIP's uuid and ONOS device port Numbers to annotations instead of a hashtable.
Removed CreatePortDescription function because it is unnecessary.
Created checkValidEndpoint fuction to identify just valid OLS SIPs.
Created getOchSignal fuction to complete the OchSignal info with the TAPI SIP information.

Change-Id: I863ea0ddb233dbcc0b82c5cc67beff1f072cb35a
(cherry picked from commit 09ab5e2d7dd8b64e56e98dfd84987d8b030986d2)
diff --git a/core/api/src/main/java/org/onosproject/net/ChannelSpacing.java b/core/api/src/main/java/org/onosproject/net/ChannelSpacing.java
index bae78e9..2b21f91 100644
--- a/core/api/src/main/java/org/onosproject/net/ChannelSpacing.java
+++ b/core/api/src/main/java/org/onosproject/net/ChannelSpacing.java
@@ -25,7 +25,8 @@
     CHL_50GHZ(50_000),          // 50 GHz
     CHL_25GHZ(25_000),          // 25 GHz
     CHL_12P5GHZ(12_500),        // 12.5 GHz
-    CHL_6P25GHZ(6_250);         // 6.25 GHz
+    CHL_6P25GHZ(6_250),         // 6.25 GHz
+    CHL_0GHZ(0);                // 0 GHz (Unknown)
 
     private final Frequency frequency;