For backward compatibility with Mbed TLS <=3.5.x, applications must be able
to make a TLS connection with a peer that supports both TLS 1.2 and TLS 1.3,
regardless of whether they call psa_crypto_init(). Since Mbed TLS 3.6.0,
we enable TLS 1.3 in the default configuration, so we must take care of
calling psa_crypto_init() if needed. This is a change from TLS 1.3 in
previous versions, where enabling MBEDTLS_SSL_PROTO_TLS1_3 was a user
choice and could have additional requirement.
This commit makes the library call psa_crypto_init() when it needs PSA
crypto in a situation where the application might not have called it,
namely, when starting a TLS 1.3 connection.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>