Docker agent: Update dockerjob to match label instead of a node list

Signed-off-by: Benjamin Copeland <ben.copeland@linaro.org>
Change-Id: I8f466af85854cee12367cf16838f6d80895ea1d0
diff --git a/ci-dockerslaves-cleanup.yaml b/ci-dockerslaves-cleanup.yaml
index 9ae9df9..77166c3 100644
--- a/ci-dockerslaves-cleanup.yaml
+++ b/ci-dockerslaves-cleanup.yaml
@@ -28,11 +28,9 @@
     axes:
         - axis:
             type: slave
-            name: nodes
+            name: label
             values:
-                - x86_64-TF-01
-                - x86_64-TF-02
-                - x86-64-TF-03
+                - build-amd64
     execution-strategy:
         sequential: false
     wrappers: