Add boardfarm recovery from a broken state

[mtusnio]

There are two parts to this task:

The physical setup needs to ensure that, even with the usb kmod failing, the ethernet connection lets boardfarm download an image to fix itself.

Apart from that the software needs to be able to recover itself from a fail state and flash a stable image, so that any PR that breaks boardfarm won't break all other PRs.

Acceptance Criteria:

• If NAND is empty, still able to program the NAND
• Use bootloader to flash, firmware0 by default and gets image from a accessible IP location (not from USB)
• Flash the image generated by Jenkins PR job
• Steps from Flashing from UBoot Prompt

[Ham22]

Surely if we use the u-boot consoles 'nand write' command over serial we could write the new images in a recoverable way?

Alternative is to do what we used to do on old projects and boot from JTAG