Add InstanceGroup APIServer role for all provider #17631
Description
/kind feature
1. Describe IN DETAIL the feature/behavior/change you would like to see.
Currently the InstanceGroup APIServer role mentioned here https://kops.sigs.k8s.io/operations/scaling/ is locked to just AWS https://github.com/kubernetes/kops/blob/master/pkg/apis/kops/validation/instancegroup.go#L241
The goal is to support APIServer only instances on all providers (e.g. GCP).
2. Feel free to provide a design supporting your feature request.