integrity: Refactor asymmetric_verify for reusability

integrity: Refactor asymmetric_verify for reusability

Refactor asymmetric_verify for reusability. Have it call
asymmetric_verify_common with the signature verification key and the
public_key structure as parameters. sigv3 support for ML-DSA will need to
check the public key type first to decide how to do the signature
verification and therefore will have these parameters available for
calling asymmetric_verify_common.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Kamlesh Kumar <kam@juniper.net>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>