Remove the ability to select a custom public exponent via domain parameters
in RSA key generation. The only way to select a custom public exponent is
now to pass custom production parameters to psa_generate_key_ext().
A subsequent commit will remove domain parameters altogether from the API,
thus this commit does not bother to update the documentation.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
4c32b69f37