Disable mbedtls-gather-timestamps job

Since PR Head/Merge jobs were disabled

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Idb2aabb9995069ba7322b30771cb0eb2392f9f6b
diff --git a/mbedtls-gather-timestamps.yaml b/mbedtls-gather-timestamps.yaml
index 86e9339..ffc31c5 100644
--- a/mbedtls-gather-timestamps.yaml
+++ b/mbedtls-gather-timestamps.yaml
@@ -2,6 +2,7 @@
     concurrent: true
     description: Mbed TLS job to gather timestamps from various jobs' runs
     name: mbedtls-gather-timestamps
+    disabled: true
     pipeline-scm:
       lightweight-checkout: true
       scm: