CI: run all.sh in a pure tf-psa-crypto environment

[mpg]

Context: After #6 the way we run the CI in tf-psa-crypto is through an Mbed TLS environment: we check out mbedtls, update tf-psa-crypto inside it, then run all.sh from Mbed TLS (which includes the crypto components).

Ultimately we want the CI (or at least the PR job) for tf-psa-crypto to be autonomous, ie run all.sh from a tf-psa-crypto checkout without checking out mbedtls. Right now we can't do just this, as all.sh from tf-psa-crypto doesn't have sufficient coverage yet (we're in the process of migrating/duplicating all relevant components to fix that).

During this migration period, we want to ensure that all the migrated component can actually run in a pure tf-psa-crypto environment (that is, without a surrounding mbedtls checkout). Without an automated check, it's all too easy for us to add a component that accidentally depends on files that are only present in mbedtls.

This task is to add a run of all.sh from tf-psa-crypto without a surrounding mbedtls checkout to tf-psa-crypto's PR CI. (While keeping the run of all.sh from mbedtls in addition for now.) Depending on what's more convenient, this may be either a separate job or the same job as the existing one.

Depends on: Mbed-TLS/mbedtls-framework#80 and its companion PRs being merged (otherwise all.sh will fail pretty early in a pure tf-psa-crypto environment).

[mpg]

Note: once this is done, we can remove the temporary wrapper from mbedtls (that is, move mbedtls-all.sh back to all.sh). The purpose of that wrapper was to make mbedtls's all.sh list tf-psa-crypto components so that they would be executed (in an mbedtls environment). Once these components are executed in a pure tf-psa-crypto environment, I see no point executing them in an mbedtls environment (or as part of the mbedtls CI) too.

@ronald-cron-arm Not sure if you want to create a follow-up task for that, or just handle it as part of this task.

[ronald-cron-arm]

Note: once this is done, we can remove the temporary wrapper from mbedtls (that is, move mbedtls-all.sh back to all.sh). The purpose of that wrapper was to make mbedtls's all.sh list tf-psa-crypto components so that they would be executed (in an mbedtls environment). Once these components are executed in a pure tf-psa-crypto environment, I see no point executing them in an mbedtls environment (or as part of the mbedtls CI) too.

@ronald-cron-arm Not sure if you want to create a follow-up task for that, or just handle it as part of this task.

That seems a small change thus I'd say just handle it as part of this task.