Add spring HWTests into the waterfall.

TEST=cbuildbot_config_unittest.py
BUG=None

Change-Id: I809dcc674ebd8e5afa3f2f541a94f2f9b0a8b0d8
Previous-Reviewed-on: https://gerrit.chromium.org/gerrit/56203
(cherry picked from commit 18dbb99b0a085c4bf39a9647a1de1598270f9d31)
Reviewed-on: https://gerrit.chromium.org/gerrit/57465
Tested-by: Scott Zawalski <scottz@chromium.org>
Reviewed-by: John D Hong <johndhong@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
diff --git a/buildbot/cbuildbot_config.py b/buildbot/cbuildbot_config.py
index fc2df37..7996d88 100755
--- a/buildbot/cbuildbot_config.py
+++ b/buildbot/cbuildbot_config.py
@@ -1299,7 +1299,6 @@
 
 _arm_release.add_config('daisy_spring-release',
   boards=['daisy_spring'],
-  hw_tests=[],
 )
 
 _arm_release.add_config('peach_pit-release',