Ignore power button if held on startup

Ignore a power button push until after we have seen it released,
to avoid shutting down immediately if the power button is held
down on startup.

1) Press and hold esc+refresh+power.
2) Depthcharge shows INSERT screen and does not power off.
3) Release esc+refresh+power.
4) Press and release power.
5) Depthcharge powers off.
TEST=test_that --fast -b grunt $grunt_ip firmware_ECLidShutdown
TEST=FEATURES=test emerge-grunt --nodeps vboot_reference

Change-Id: I7421a4b1a1b8a7894f0e7d1c7927ffc52d9faac0
Signed-off-by: Edward Hill <ecgh@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1256023
Reviewed-by: Raul E Rangel <rrangel@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2 files changed