ath79: add support for Netgear WNR1000 v2

ath79: add support for Netgear WNR1000 v2

This patch adds ath79 support for Netgear WNR1000v2.
Router was previously supported by ar71xx target only.
Note: this is a 4_32 device with limited upgrade capabilities.

Specification
=============
  * Description: Netgear WNR1000 v2
  * Loader: U-boot
  * SOC: Atheros AR7240 (340 MHz)
  * RAM: 32 MiB
  * Flash: 4 MiB (SPI NOR)
	- U-boot binary: 256 KiB
	- U-boot environment: 64 KiB
	- Firmware: 3712 KiB
	- ART: 64 KiB
  * Ethernet: 4 x 10/100 LAN + 1 x 10/100 WAN
  * Wireless: 2.4 GHz b/g/n (Atheros AR9285)
  * USB: no
  * Buttons:
	- Reset
	- WiFi (rfkill)
	- WPS
  * LEDs:
	- Power (amber/green)
	- WAN (amber/green)
	- WLAN (blue)
	- 4 x LAN (amber/green)
	- WPS (green)
  * UART: 4-pin connector JP2, 3.3V (Vcc, TX, RX, GND), 115200 8N1
  * Power supply: DC 12V 1A
  * MAC addresses: LAN on case label, WAN +1, WLAN +2

Installation
============
  * TFTP recovery
  * TFTP via U-boot prompt
  * sysupgrade
  * Web interface

Test build configuration
========================
CONFIG_TARGET_ath79=y
CONFIG_TARGET_ath79_tiny=y
CONFIG_TARGET_ath79_tiny_DEVICE_netgear_wnr1000-v2=y
CONFIG_ALL_KMODS=y
CONFIG_DEVEL=y
CONFIG_CCACHE=y
CONFIG_COLLECT_KERNEL_DEBUG=y
CONFIG_IMAGEOPT=y
CONFIG_KERNEL_DEBUG_INFO=y
CONFIG_KERNEL_DEBUG_KERNEL=y

Signed-off-by: Michal Cieslakiewicz <michal.cieslakiewicz@wp.pl>