I'd like to use openssl to self-sign a sm2 certificate like this way:
"openssl x509 -req -in sm2.csr.pem -signkey sm2.key.pem -out sm2.cert.pem "

but it would give me a problem:
"Request self-signature did not match the certificate request"

Actually this problem is caused by signing sm2 cert without seting a sm2-id. I'd like to fix this problem and make a pull request.

When the problem is solved, the usage looks would like this(similar to pr9085-https://github.com/openssl/openssl/pull/9085)：
"openssl x509 -req -in sm2.csr.pem -signkey sm2.key.pem -out sm2.cert.pem -sm3 -sm2-id 1234567812345678 -sigopt "sm2_id:1234567812345678""