soc/amd/stoneyridge: Prevent reboot in romstage
By setting this register in bootblock AmdInitEnv will no longer trigger
a reset in romstage. This fixes a few vboot test failures and also
speeds up boot time.
BUG=b:
111610455
TEST=Built grunt and made sure bootblock only happens once on cold boot,
and S3 resume.
Change-Id: Ie19f7a14deaef45ac63156bec6946273c1b9447e
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Reviewed-on: https://review.coreboot.org/27876
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>