Features
   * mbedtls_psa_get_random() is always available as soon as
     MBEDTLS_PSA_CRYPTO_CLIENT is enabled at build time and psa_crypto_init() is
     called at runtime. This together with MBEDTLS_PSA_RANDOM_STATE can be
     used as random number generator function (f_rng) and context (p_rng) in
     legacy functions.