[TF-A] Re-scheduling TF-A Tech Forum earlier by 1 hour

Hi all,

Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to 1600 UK time (1500 UTC). This change is to avoid overlapping with the TF Technical Steering Committee call.

We'll delete the existing invite and send a new one to this list.

Regards

Bill