Problem: 

Customer wants an option to specify an additional security group for the Loadbalancers in install-config.yaml. 

Additional day 2 operations required to workaround and resolve the default Load Balancers, which do not have an attached Security Group and is created within the same subnets as the OpenShift clusters.

Customer wants  the option to specify per load balancer security group, knowing that IPI automatically creates 3 x Load Balancer for a public cluster and 2 x Load Balancer for a private cluster.

Something like the following within install-config.yaml

platform:
  aws:
    region: ap-southeast-1
    lbType: NLB
    vpc:
      subnets:
        - id: subnet-xxx # public subnet
          roles:
            - type: BootstrapNode
            - type: IngressControllerLB
              additionalSecurityGroupIDs:
                - sg-xxx
            - type: ControlPlaneExternalLB
              additionalSecurityGroupIDs:
                - sg-xxx
        - id: subnet-xxx # private subnet
          roles:
            - type: ControlPlaneInternalLB
              additionalSecurityGroupIDs:
                - sg-xxx
        - id: subnet-xxx # private subnet
          roles:
            - type: ClusterNode