Preparing for OP-TEE 3.15.0

[BCC all OP-TEE maintainers]

Hi OP-TEE maintainers & contributors,

OP-TEE v3.15.0 is scheduled to be released on 2021-10-15. So, now is a good time to start testing the master branch on the various platforms and report/fix any bugs.

The GitHub pull request for collecting Tested-by tags or any other comments is https://github.com/OP-TEE/optee_os/pull/4880

As usual, we will create a release candidate tag one week before the release date for final testing.

In addition to that you can find some additional information related to releases here: https://optee.readthedocs.io/en/latest/general/releases.html

Regards, Ruchika