This saves ~70mw of power.
To make this work, I also had to stretch the power button signal to
give the system a chance to come back up when the user taps the power
button.
Signed-off-by: Randall Spangler <rspangler@chromium.org>
BUG=chrome-os-partner:9574
TEST=manual
For each of the following tests, wait ~15 sec after the system is
powered off to give it a chance to drop DPWROK.
1) tap power button -> system turns on
2) hold power button 1 sec -> system turns on
3) open lid -> system turns on
4) silego reset (power+refresh, or power+esc on proto1) -> system stays off
5) silego recovery (power+esc+refresh) -> system turns on
6) hold down power button and type 'reboot' on EC console -> system turns on
7) type 'powerbtn' on EC console -> system turns on
Change-Id: I781cf3e665104192521b7fb9ff75a3c3e7f43464
30a33e6b04