ramips: add support for Netgear WN3000RPv3

This patch adds support for the Netgear WN3000RPv3
http://www.netgear.com/support/product/wn3000rpv3.aspx

Specifications:
- SoC: MediaTek MT7620A (580MHz, ramips)
- RAM: 32MB DDR
- Storage: 8MB NOR SPI flash
- Wireless: builtin MT7620A, 2x2:2 with u.FL connectors
- Ethernet: 1x100M
- Serial: JP1 header, 57600-8N1
- Stock firmware based on OpenWRT Kamikaze

Like the EX2700, the bootloader expects a secondary image signature,
see https://forum.openwrt.org/viewtopic.php?pid=312577#p312577
This is why the same fakeroot image is used for the WN3000

Signed-off-by: Thibaut VARENE <hacks@slashdirt.org>

target/linux/ramips/base-files/etc/board.d/01_leds

@@ -155,7 +155,8 @@ vr500)
 dir-860l-b1)
 	ucidef_set_led_netdev "wan" "wan" "$board:green:net" "eth0.2"
 	;;
-ex2700)
+ex2700|\
+wn3000rpv3)
 	ucidef_set_led_default "power_r" "POWER (red)" "$board:red:power" "0"
 	set_wifi_led "$board:green:router"
 	;;

target/linux/ramips/base-files/etc/board.d/02_network

@@ -58,6 +58,7 @@ ramips_setup_interfaces()
 	timecloud|\
 	w150m|\
 	widora-neo|\
+	wn3000rpv3|\
 	wnce2001|\
 	zbt-cpe102|\
 	zte-q7)