Switch all.sh components from using selftest to using which_aes

[felixc-arm]

See this comment Mbed-TLS/TF-PSA-Crypto#199 (review) for more information.
Change code in all.sh components to use the new program which_aes from the PR Mbed-TLS/TF-PSA-Crypto#199 to check the AES implementation instead of using the result returned by selftest.