Add stone-prod-p02 PPC maintenance to banner (#7879)

Add banner for IBM Cloud PPC re-provisioning to stone-prod-p02 for
August 29th 7:30AM - 10AM ET.

Author: enkeefe00

components/konflux-info/production/stone-prod-p02/banner-content.yaml

@@ -1,2 +1,11 @@
+- summary: "IBM Cloud PPC Re-provisioning: See Konflux announcement email 'IBM Cloud PPC Maintenance on stone-prod-p02' for more details. PPC Multi-Arch builds will be impacted."
+  type: "warning"
+  year: 2025
+  month: 8
+  dayOfMonth: 29
+  startTime: "07:30"
+  endTime: "10:00"
+  timeZone: "America/New_York"
+
 - type: info
   summary: ✨ Hope you're having a great day. If you need a little whimsy, check out [this wonderful thing](https://videos.learning.redhat.com/media/A+whole+new+build/1_v9l8cton) shared by the ART team.