platform/chrome: cros_ec_dev - Add a platform device ID table

If the cros_ec_dev driver is built as a module, modalias information is
not filled so the module is not autoloaded. Add a platform device table
and use the MODULE_DEVICE_TABLE() macro to export that information in
the module so user-space can match the modalias uevent and autoload it.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Olof Johansson <olof@lixom.net>