[CMD][SECO_FDT_OVERLAY] Add a new cmd based implementation for handling the eeprom and seco_config dtbo selection
We had a implementation for this in the u-boot environment, but for several reasons that was not very nice. This adds a new cmd to u-boot to read out the config for panel and touch from the eeprom, seco_config and eventually a hardcoded default, and applies the overlays as needed.