Keep timestamp bundles for 120 days

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
Change-Id: I969469d4871dba603310bf8802ed9b203640b845
diff --git a/mbedtls-gather-timestamps.yaml b/mbedtls-gather-timestamps.yaml
index a20e84f..86e9339 100644
--- a/mbedtls-gather-timestamps.yaml
+++ b/mbedtls-gather-timestamps.yaml
@@ -17,7 +17,7 @@
     - build-discarder:
         artifact-days-to-keep: -1
         artifact-num-to-keep: -1
-        days-to-keep: 60
-        num-to-keep: 100
+        days-to-keep: 120
+        num-to-keep: 120
     triggers:
     - timed: 0 8 * * *