Provide a common function to issue reboot commands to the EC. Expose that function for external use and use it internal to the module. BUG=b:35580805 Change-Id: I1458bd7119b0df626a043ff3806c15ffb5446c9a Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/19573 Reviewed-by: Furquan Shaikh <furquan@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>