platform/chrome: cros_ec_typec: Add PM support

Define basic suspend resume functions for cros-ec-typec. On suspend, we
simply ensure that any pending port update work is completed, and on
resume, we re-poll the port state to account for any
changes/disconnections that might have occurred during suspend.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>