1. Proposed title of this feature request
Allow coreos-installer to wipe the disk if something like `coreos.inst.wipe=yes` is added to pxe bootline.

2. What is the nature and description of the request?
The PXE based installations are generally automated installs and at times using old systems or systems which have LVM present on disk fail to install.
For some of the users it breaks the automation and fix is manually wiping the disk.
Ref: access.redhat.com/solutions/7048172

On UPI install this isn't a problem, but at some times this breaks the automation, of course the option shall work on the disk specified under 'coreos.inst.install_dev' to avoid accidental deletions.

3. Why does the customer need this? (List the business requirements here)
Breaks automation for the customer, the other options as in editing or supplying additional ignition aren't trusted or even the pre-scripts doesn't seems to be working.

4. List any affected packages or components.
coreos-installer