make it possible to select supported devices in the operator

There are cases where only the selected devices/their CRDs are wanted/needed in the operator. The operator deployment shall support this by making it possible to:

- [x] add `--devices` cmdline to operator `main.go` which defines the controllers/webhooks to set up. refactor `main`
- [ ] do not deploy fpga/sgx mutating pod webhooks' `MutatingWebhookConfiguration`s
- [ ] kustomize the unwanted RBAC / CRD settings: add `operator/device/xyx` kustomize overlay that 1) deploys the CRD for xyz device and patches manager.yaml to add `--devices xyz` param to manager.
- [ ] document per device deployment