Add a delay to allow the clocks and usb signals to settle.
BUG=b:63767046,b:63867566
BRANCH=cr50
TEST=put the eve ec into hibernate, wait until cr50 enters deep sleep,
use the uart to wake it up, and verify that it eventually reenters deep
sleep
Change-Id: I26463ce3e00996368a791a245b0f9de01737478c
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/598448
Reviewed-by: Marius Schilder <mschilder@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>