Detect loss of VBUS when acting as PD sink and go to the disconnected
state. This allows us to renegotiate power when power supply drops
and switches to 5V.
BUG=none
BRANCH=none
TEST=On a samus, tested by running for a couple of hours, and verifying
that occasionally when zinger drops from 20V to 5V, we detect it and
go to the disconnected state. Note, this only happens a couple times
every hour.
Change-Id: I237d267824ff564662c9c02e525ce2613ed229e6
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/200365
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>