ar71xx: add ew-balin platform from Embedded Wireless

ar71xx: add ew-balin platform from Embedded Wireless

Add the Embedded Wireless "Balin" platform
 SoC: QCA AR9344 or AR9350
 RAM: DDR2-RAM 64MBytes
 Flash: SPI-NOR 16MBytes
 WLAN: 2 x 2 MIMO 2.4 & 5 GHz IEEE802.11 a/b/g/n
 Ethernet: 3 x 10/100 Mb/s
 USB: 1 x USB2.0 Host/Device bootstrap-pin at power-up
 PCI-Express: 1 x lane PCIe 1.2
 UART: 1 x Normal, 1 x High-Speed
 JTAG: 1 x EJTAG
 GPIO: 10 x Input/Output multiplexed

The module comes already with the current vanilla OpenWrt firmware.
To update, use "sysupgrade" image directly in vendor firmware.

Signed-off-by: Catrinel Catrinescu <cc@80211.de>