Init script and defconfig for manufacturing

To help with manufacturing, we provide a binary image that is
pre-programmed into the NOR flash.

This version of the bootloader is different from the regular one:

- The baked-in init script runs a dhcp client to get an IP address and
  downloads and executes a bootstrap script. This gives us a lot of
  flexibility for the manufacturing process.

- The defconfig excludes the following drivers: I2C, SPI and NAND. This
  is useful if we later decide to make incompatible changes to the NAND
  driver and require this bootloader to not touch the NAND chip.

Change-Id: Ibfad78a24557683d5b479d9b5bebd95438471a32
2 files changed