Add a tool that can be used to verify if a given IBM host-key document is
valid. This uses the same logic (and code) as the image/request tools
for IBM Secure Execution, pvimg, pvattest, and pvsecret.
This tool basically just does the first step of the above tools; but without
creating any request or image.
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
