vboot: only clear recovery requests at kernel verification

Instead of clearing recovery requests early on in firmware
verification, defer this task until kernel verification has
begun.

If the system is rebooted for any non-vboot-related reason when
entering recovery mode (e.g. FSP initialization), the recovery
request will still be available in nvdata.

Additionally, relocate the reboot triggered by memory training
into VbSelectAndLoadKernel.

BUG=b:124141368, b:35576380
TEST=make clean && make runtests
BRANCH=none

Change-Id: I787e45c7ed4f2bebf570bb9c1a8e9e371f2a040b
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1940398
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: Joel Kitching <kitching@chromium.org>
5 files changed