Clarify the failure states for multi-part operation setup functions

[athoelke]

In version 1.1, the error condition descriptions were clarified and aligned across the whole API, but in the process an error was introduced in the description of multi-part operation objects when the setup function returned an error. The typical wording is as follows:

If psa_sign_setup() returns an error, the operation object is unchanged. If a subsequent function call with an active operation returns an error, the operation enters an error state.

To abandon an active operation, or reset an operation in an error state, call psa_sign_abort().

The first statement is only true if the operation was inactive prior to the call. If the operation was not inactive then calling the setup function is going to return PSA_ERROR_BAD_STATE (as the call is out of sequence) and put the operation object into an error state. TF-PSA-Crypto still implements the original MbedTLS behaviour from before Crypto API 1.1 - which is to put the object into an error state if it was not inactive prior to the setup call.

This PR clarifies the behaviour and restores the missing (v1.0) conditions to all of the setup functions.