Shouldn't need to put host data in platform baremetal section in installconfig

When doing openshift-install agent create image, one should not need to provide platform specific data like boot MAC addresses.

4.12

100%

1.Create install-config with only VIPs in Baremetal platform section

apiVersion: v1
metadata:
  name: foo
baseDomain: test.metalkube.org
networking:
  clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
  machineNetwork:
    - cidr: 192.168.122.0/23
  networkType: OpenShiftSDN
  serviceNetwork:
    - 172.30.0.0/16
compute:
  - architecture: amd64
    hyperthreading: Enabled
    name: worker
    platform: {}
    replicas: 0
controlPlane:
  name: master
  replicas: 3
  hyperthreading: Enabled
  architecture: amd64
platform:
  baremetal:
    apiVIPs:
      - 192.168.122.10
    ingressVIPs:
      - 192.168.122.11
---
apiVersion: v1beta1
metadata:
  name: foo
rendezvousIP: 192.168.122.14

2.openshift-install agent create image

ERROR failed to write asset (Agent Installer ISO) to disk: cannot generate ISO image due to configuration errors 
ERROR failed to fetch Agent Installer ISO: failed to load asset "Install Config": failed to create install config: invalid "install-config.yaml" file: [platform.baremetal.hosts: Invalid value: []*baremetal.Host(nil): bare metal hosts are missing, platform.baremetal.Hosts: Required value: not enough hosts found (0) to support all the configured ControlPlane replicas (3)]

Image gets generated

We should go into install-config validation code, detect if we are doing agent-based installation and skip the hosts checks