Update Docs for EVP_MAC
For GMAC/CMAC, its not possible to re-init the algorithm without
explicitly passing an OSSL_MAC_PARAM_IV to each init call, as it is
not possible to extract the IV value from the prior init call (be it
explicitly passed or auto generated). As such, document the fact that
re-initalization requires passing an IV parameter
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23235)
(cherry picked from commit
7c1d533a512181b13de3bc0b7fa2fd8c481032d3)