`register-type` should create the logging role

[richardhboyd]

If I register a private type from another account, I would expect aws cloudformation register-type ... to create a role similar to the one created during the cfn submit ... operation. I understand that I could provide an IAM Role ARN for with the register-type command, but then I need to know much more about the underlying details of how the Resource Provider is implemented, which I shouldn't have to be aware of as an end-user.