PSA_KEY_DERIVATION_INPUT_OTHER_SECRET macro

A high-entropy additional secret input for key derivation. This is typically the shared secret resulting from a key agreement obtained via `psa_key_derivation_key_agreement()`. It may alternatively be a key of type `PSA_KEY_TYPE_DERIVE` passed to `psa_key_derivation_input_key()`, or a direct input passed to `psa_key_derivation_input_bytes()`.