Implement x86 force shutdown
Implement x86 force shutdown

Signed-off-by: Rong Chang <3a05493f7adfb36d203f663b3bc2ba30e9d6284f@chromium.org>
BUG=chrome-os-partner:8242
TEST=manual
  Switch to dev mode VT2 console. Increase CPU load:
    cat /dev/urandom > /dev/null &
    cat /dev/urandom > /dev/null &
  Check CPU PECI temperature and wait for auto shutdown:
    ectool temps 9

Change-Id: I62ad6efd6621bf5ddcde55424c39ac897271a94a
Reviewed-on: https://gerrit.chromium.org/gerrit/25503
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>
Reviewed-by: Randall Spangler <62698fdbb84d1779579ee80c3f39fac22017e5bc@chromium.org>
Commit-Ready: Rong Chang <3a05493f7adfb36d203f663b3bc2ba30e9d6284f@chromium.org>
Tested-by: Rong Chang <3a05493f7adfb36d203f663b3bc2ba30e9d6284f@chromium.org>

alterapraxisptyltd/chromium-ec,coreboot/chrome-ec,md5555/ec,longsleep/ec,eatbyte/chromium-ec,md5555/ec,eatbyte/chromium-ec,eatbyte/chromium-ec,mtk09422/chromiumos-platform-ec,fourier49/BIZ_EC,fourier49/BIZ_EC,longsleep/ec,mtk09422/chromiumos-platform-ec,fourier49/BZ_DEV_EC,thehobn/ec,fourier49/BZ_DEV_EC,fourier49/BIZ_EC,alterapraxisptyltd/chromium-ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,fourier49/BZ_DEV_EC,gelraen/cros-ec,md5555/ec,alterapraxisptyltd/chromium-ec,akappy7/ChromeOS_EC_LED_Diagnostics,thehobn/ec,coreboot/chrome-ec,mtk09422/chromiumos-platform-ec,akappy7/ChromeOS_EC_LED_Diagnostics,thehobn/ec,longsleep/ec,fourier49/BZ_DEV_EC,md5555/ec,gelraen/cros-ec,gelraen/cros-ec,alterapraxisptyltd/chromium-ec,coreboot/chrome-ec,gelraen/cros-ec,coreboot/chrome-ec,thehobn/ec,eatbyte/chromium-ec,mtk09422/chromiumos-platform-ec,fourier49/BIZ_EC,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,longsleep/ec