platform/chrome: cros_ec_typec: Use cros_ec_command()

Re-use the existing cros_ec_command() instead of relying on a duplicate
version.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210930022403.3358070-6-pmalani@chromium.org