ath79: add support for Compex WPJ344

ath79: add support for Compex WPJ344

Specifications:

SoC: AR9344
DRAM: 128MB DDR2
Flash: 16MB SPI-NOR
2 Gigabit ethernet ports
2×2 2.4GHz on-board radio
miniPCIe slot that supports 5GHz radio
PoE 48V IEEE 802.3af/at - 24V passive optional
USB 2.0 header

Installation:

To install, either start tftp in bin/targets/ath79/generic/ and use
the u-boot prompt over UART:

tftpboot 0x80500000 openwrt-ath79-generic-compex_wpj344-16m-squashfs-sysupgrade.bin
erase 0x9f030000 +$filesize
erase 0x9f680000 +1
cp.b $fileaddr 0x9f030000 $filesize
boot

The cpximg file can be used with sysupgrade in the stock firmware (add
SSH key in luci for root access) or with the built-in cpximg loader.
The cpximg loader can be started either by holding the reset button
during power up or by entering the u-boot prompt and entering 'cpximg'.
Once it's running, a TFTP-server under 192.168.1.1 will accept the image
appropriate for the board revision that is etched on the board.

For example, if the board is labelled '6A08':

tftp -v -m binary 192.168.1.1 -c put openwrt-ath79-generic-compex_wpj344-16m-squashfs-cpximg-6a08.bin

MAC addresses:

<&uboot 0x2e010>  *:99  (label)
<&uboot 0x2e018>  *:9a
<&uboot 0x2e020>  *:9b
<&uboot 0x2e028>  *:9c

Only the first two are used (for ethernet), the WiFi modules have
separate (valid) addresses. The latter two addresses are not used.

Signed-off-by: Leon M. George <leon@georgemail.eu>
[minor commit message adjustments, drop gpio in DTS, DTS style fixes,
sorting, drop unused cpximg recipe]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>