Add script for signing PSP Verstage
Add script for signing PSP Verstage

This script will sign the psp_veratage.bin file and modify the fields as required.

BUG=b:166095736
TEST=create verstage signed with test key.

Change-Id: I234d7902f950a60a816dd5f4d46d3d5afd105489
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2390825
Tested-by: Martin Roth <79230511ccf79da3f7e9e82dbcc9c1ec2f734fa0@google.com>
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Commit-Queue: Martin Roth <79230511ccf79da3f7e9e82dbcc9c1ec2f734fa0@google.com>

coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot