Study: Consume PSA-Crypto repository

[daverodgman]

Remove the code which is currently mirrored in https://github.com/Mbed-TLS/psa-crypto . Mbed TLS must instead import code from TF-PSA-Crypto.

To ensure that users can continue to do a simple git checkout of Mbed TLS, we will (probably) want to do this via a script which regularly takes a copy of the code from TF-PSA-Crypto and checks it in to Mbed TLS:

• copy the PSA-Crypto code into a directory within Mbed TLS (library/tf-psa-crypto maybe?)

• move the headers into /include

• Manually copy TF-PSA-Crypto into /tf-psa-crypto

• Remove files from library that now live in /tf-psa-crypto

• For all public headers coming from TF-PSA-Crypto, remove existing headers from /include and move the imported headers to this location

• Update Mbed TLS build scripts to use the new source code directory

• Check this in

• Write a script to update Mbed TLS with a fresh copy from PSA-Crypto (for now, just from the tip - no need to handle branches and tags)

• Automate running the script from Jenkins on a TBD cadence (probably every week)