Remove smoke tag for TelemetryNotificationAPITest

It doesn't make sense to run this test by default since Ceilometer API
is deprecated.

As a user who follows Telemetry deprecations, I don't want to run this
test by default.

Change-Id: Ib7aaf876a8bc198f0134e86449aec09ff0db23e1
diff --git a/ceilometer/tests/tempest/api/test_telemetry_notification_api.py b/ceilometer/tests/tempest/api/test_telemetry_notification_api.py
index d5a1eb0..33575ba 100644
--- a/ceilometer/tests/tempest/api/test_telemetry_notification_api.py
+++ b/ceilometer/tests/tempest/api/test_telemetry_notification_api.py
@@ -38,7 +38,6 @@
         for metric in self.nova_notifications:
             self.await_samples(metric, query)
 
-    @test.attr(type="smoke")
     @decorators.idempotent_id('c240457d-d943-439b-8aea-85e26d64fe8f')
     @test.services("image")
     @testtools.skipIf(not CONF.image_feature_enabled.api_v2,