detachables: Reset timer every time user moves the cursor
detachables: Reset timer every time user moves the cursor

In dev mode, after 30 seconds of inactivity, we'll get
the usual loud beep and automatic boot from disk.

BUG=b:35585623
BRANCH=None
TEST=reboot and make sure that fw screen timeout only occurs
     after 30 seconds of inactivity.

Change-Id: Id6552f7213a52ed8c0f083a8388719a8fe79fa77
Signed-off-by: Shelley Chen <ab7b8cc85923339aed379eb1c5cc4dccfd2eb3d7@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/457841
Reviewed-by: Randall Spangler <62698fdbb84d1779579ee80c3f39fac22017e5bc@chromium.org>

coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot