colibri-imx6ull: set module variant depending on config block

colibri-imx6ull: set module variant depending on config block

Using CPU temperature grading as a discriminator if the Wi-Fi /
Bluetooth chip is populated is no longer possible due to upcoming
SKUs. Set variant to -wifi only if a valid config block is present
and the product id mentions a SKU with Wi-Fi / Bluetooth.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Igor Opaniuk <igor.opaniuk@toradex.com>