Calling halt in poweroff when in SMM prevents SLP_SMI to be triggered
preventing the system from entering sleep state. Fix this by calling
halt only if ENV_SMM is not true.
BUG=chrome-os-partner:56395
BRANCH=None
TEST=Verified lidclose behavior on reef.
Change-Id: If116c8f4e867543abdc2ff235457c167b5073767
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/16257
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>