mpc85xx: add support for OCEDO Panda

mpc85xx: add support for OCEDO Panda

CPU:   FSL P1020 (2x 800MHz E500 PPC)
RAM:   1GB DDR3
FLASH: 256MiB NAND
WiFi:  2x Atheros AR9382 2x2:2 abgn
ETH:   2x BCM54616S - 1x BCM53128 8-port switch
LED:   5x LEDs (Power, WiFi1, WiFi2, N/D, SYS)
BTN:   1x RESET

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

1. Download initrams kernel image, dtb binary and sysupgrade image.

2. Place initramfs kernel into tftp root directory. Rename to
"panda-uimage-factory".

3. Place dtb binary into tftp root directory. Rename to "panda.fdt".

4. Start tftp server on 192.168.100.8/24.

5. Power up the device with the reset button pressed. It will download
the initrams and dtb via tftp and boot into OpenWRT in RAM.

6. SSH into the device and remove the factory partitions.

 > ubirmvol /dev/ubi0 --name=kernel1
 > ubirmvol /dev/ubi0 --name=rootfs1
 > ubirmvol /dev/ubi0 --name=devicetree1

You will have around 60 MiB of free space with that.

You can also delete "kernel2", "devicetree2", "rootfs2" and "storage"
respectively in case you do not want to go back to the vendor firmware.

7. Modify the U-Boot bootcmd to allow for booting OpenWRT

 > fw_setenv bootcmd_owrt "ubi part ubi && ubi read 0x1000000 kernel
   && bootm 0x1000000"

 > fw_setenv bootargs_owrt "setenv bootargs console=ttyS0,115200
   ubi.mtd=3,2048"

 > fw_setenv bootcmd "run bootargs_owrt; run bootcmd_owrt"

8. Transfer the sysupgrade image via scp into the /tmp directory.

9. Upgrade the device

 > sysupgrade -n /tmp/<imagename>

Signed-off-by: David Bauer <mail@david-bauer.net>