mpc85xx: add support for Watchguard Firebox T10

mpc85xx: add support for Watchguard Firebox T10

Hardware
--------
SoC:    Freescale P1010
RAM:    512MB
FLASH:  1 MB SPI-NOR
        512 MB NAND
ETH:    3x Gigabite Ethernet (Atheros AR8033)
SERIAL: Cisco RJ-45 (115200 8N1)
RTC:    Battery-Backed RTC (I2C)

Installation
------------

1. Patch U-Boot by dumping the content of the SPI-Flash using a SPI
   programmer. The SHA1 hash for the U-Boot password is currently
   unknown.

   A tool for patching U-Boot is available at
   https://github.com/blocktrron/t10-uboot-patcher/

   You can also patch the unknown password yourself. The SHA1 hash is
   E597301A1D89FF3F6D318DBF4DBA0A5ABC5ECBEA

2. Interrupt the bootmenu by pressing CTRL+C. A password prompt appears.
   The patched password is '1234' (without quotation marks)

3. Download the OpenWrt initramfs image. Copy it to a TFTP server
   reachable at 10.0.1.13/24 and rename it to uImage.

4. Connect the TFTP server to ethernet port 0 of the Watchguard T10.

5. Download and boot the initramfs image by entering "tftpboot; bootm;"
   in U-Boot.

6. After OpenWrt booted, create a UBI volume on the old data partition.
   The "ubi" mtd partition should be mtd7, check this using

   $ cat /proc/mtd

   Create a UBI partition by executing

   $ ubiformat /dev/mtd7 -y

7. Increase the loadable kernel-size of U-Boot by executing

   $ fw_setenv SysAKernSize 800000

8. Transfer the OpenWrt sysupgrade image to the Watchguard T10 using
   scp. Install the image by using sysupgrade:

   $ sysupgrade -n <path-to-sysupgrade>

   Note: The LAN ports of the T10 are 1 & 2 while 0 is WAN. You might
   have to change the ethernet-port.

9. OpenWrt should now boot from the internal NAND. Enjoy.

Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit 35f6d795134e9b089c4e763a7f58cba7d4e15e42)