Support disk mirroring during OCP installation with the IPI method

1. Proposed title of this feature request:

Support disk mirroring during OCP installation with the IPI method

2. What is the nature and description of the request?

Customer would like that the feature of supporting disk mirroring during OCP installation with the IPI method is added to OCP product, as currently "Mirroring is available only for user-provisioned infrastructure deployments on RHCOS systems. " as per documentation [1]

3. Why does the customer need this? (List the business requirements here)

This would solve the incompatibility issues RHEL8.x has with many common storage controllers, without sacrificing IPI features

4. List any affected packages or components.

Installer, (Butane command-line utility on installation node?  - not sure about that.)

[1] https://docs.openshift.com/container-platform/4.9/installing/install_config/installing-customizing.html#installation-special-config-mirrored-disk_installing-customizing