[openweave] Export the required symbols

Change-Id: I856b99921ab1fc52079e51b493ddf5f45bd83587
diff --git a/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConnectivityManagerImpl_Thread.h b/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConnectivityManagerImpl_Thread.h
index d003cb0..cdd898f 100644
--- a/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConnectivityManagerImpl_Thread.h
+++ b/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConnectivityManagerImpl_Thread.h
@@ -48,7 +48,7 @@
  *
  */
 template<class ImplClass>
-class GenericConnectivityManagerImpl_Thread
+class NL_DLL_EXPORT GenericConnectivityManagerImpl_Thread
 {
 protected: