qoriq: add support for WatchGuard Firebox M300

qoriq: add support for WatchGuard Firebox M300

This device is based on NXP's QorIQ T2081QDS board, with a quad-core
dual-threaded 1.5 GHz ppc64 CPU and 4GB ECC RAM. The board has 5
ethernet interfaces, of which 3 are connected to the ethernet ports on
the front panel. The other 2 are internally connected to a Marvell
88E6171 switch; the other 5 ports of this switch are also connected to
the ethernet ports on the front panel.

Installation: write the sdcard image to an SD card. Stock U-Boot will
not boot, wait for it to fail then run these commands:

setenv OpenWrt_fdt image-watchguard-firebox-m300.dtb
setenv OpenWrt_kernel watchguard_firebox-m300-kernel.bin
setenv wgBootSysA 'setenv bootargs root=/dev/mmcblk0p2 rw rootdelay=2 console=$consoledev,$baudrate fsl_dpaa_fman.fsl_fm_max_frm=1530; ext2load mmc 0:1 $fdtaddr $OpenWrt_fdt; ext2load mmc 0:1 $loadaddr $OpenWrt_kernel; bootm $loadaddr - $fdtaddr'
saveenv
reset

The default U-Boot boot entry will now boot OpenWrt from the SD card.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: Rui Salvaterra <rsalvaterra@gmail.com>