Update boot image signature format to version 1

Add the full X.509v3 certificate to the signature footer for easier
verification.

Change-Id: Ic969e9c1e4ab1a25ffdde2ab818b8edf2ad95253
(cherry picked from commit f67d3764c641e53d4a1b925b4d02fec92b7e894a)
3 files changed