ramips: add support for I-O DATA WNPR2600G

I-O DATA WNPR2600G is a 2.4/5 GHz band 11ac router, based on MediaTek
MT7621A.

Specification:

- SoC           : MediaTek MT7621A
- RAM           : DDR3 128 MiB
- Flash         : SPI-NOR 16 MiB
- WLAN          : 2.4/5 GHz 4T4R
  - 2.4 GHz     : MediaTek MT7615
  - 5 GHz       : MediaTek MT7615
- Ethernet      : 10/100/1000 Mbps
  - Switch      : MT7530 (SoC)
- LED/keys      : 4x/3x (2x buttons, 1x slide-switch)
- UART          : through-hole on PCB
  - J1: Vcc, RX, GND, TX from SoC side
  - 57600n8

Flash instruction using factory image:

1. Boot WNPR2600G normaly
2. Access to "http://192.168.0.1/" and open firmware update page
("ファームウェア")
3. Select the OpenWrt factory image and click update ("更新") button
to perform firmware update
4. Wait ~150 seconds to complete flashing

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>

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

@@ -242,6 +242,7 @@ ramips_setup_interfaces()
 	huawei,hg255d|\
 	iodata,wn-ax1167gr|\
 	iodata,wn-gx300gr|\
+	iodata,wnpr2600g|\
 	iptime,a604m)
 		ucidef_add_switch "switch0" \
 			"1:lan:4" "2:lan:3" "3:lan:2" "4:lan:1" "0:wan" "6@eth0"
@@ -670,6 +671,10 @@ ramips_setup_macs()
 	trendnet,tew-692gr)
 		wan_mac=$(macaddr_add "$(mtd_get_mac_binary factory 0x4)" 1)
 		;;
+	iodata,wnpr2600g)
+		wan_mac=$(mtd_get_mac_ascii u-boot-env wanaddr)
+		label_mac=$wan_mac
+		;;
 	iptime,a3|\
 	iptime,a604m)
 		wan_mac=$(mtd_get_mac_binary u-boot 0x1fc40)