platform/chrome: cros_ec_typec: Move structs to header

Move ChromeOS Type-C structs into their own header, so they can be
referenced by other files which can be added to the same module.

No functional changes introduced by this patch.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20221228004648.793339-7-pmalani@chromium.org