/kind feature

Describe the solution you'd like
Support EKS Provisioned Control Plane

ControlPlaneScalingConfig supports specifying a tier for the EKS control plane - standard | tier-xl | tier-2xl | tier-4xl

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Cluster-api-provider-aws version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):