Don't try to include MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE when
MBEDTLS_PSA_CRYPTO_CONFIG is disabled. This didn't make sense and was an
editorial mistake when adding it: it's meant as an addition to
MBEDTLS_PSA_CRYPTO_CONFIG_FILE, so it should be included under the same
conditions.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
