toradex: configblock: add an -y parameter to 'cfgblock create’

Add an optional -y parameter to 'cfgblock create’ to simplify
automation.

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