In an effort to shave off code size, remove out-of-the-box
enabling of crypto features (except SHA-256).
Configurations are adjusted to enable what they need.
Bonuses:
- When enabled, AES now defaults to using a smaller version
(`CONFIG_MBEDTLS_AES_ROM_TABLES` isn't default enabled anymore,
and if enabled, `CONFIG_MBEDTLS_AES_FEWER_TABLES` defaults to y).
- Conditions around Mbed TLS Kconfig options have been improved
to reflect the reality of the dependencies.
Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>