octopus: ignore C0 interrupts if in reset

Now that we have a reset line to C0, we should ignore interrupts while
the C0 TCPC is in reset.

BRANCH=none
BUG=none
TEST=flashed on fleex (uses C0 reset)  without issue

Change-Id: I014e95f80844b30623d1fba7e59bea8f5eb8572e
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1332807
Reviewed-by: Diana Z <dzigterman@chromium.org>