At first boot CSE spends long time preparing media for use. As result
it may not be able to deal with a CPU reset. Add reset_prepare()
callback that polls CSE readiness.
BUG=chrome-os-partner:55055
TEST=build with release version of fsp, reboot, observe polling for
CSE, then proper reboot happening
Change-Id: I639ef900b97132f1a7f269bb864d70009df9fdfe
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/15721
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>