ramips: add support for netis WF2770

netis WF2770 is a 2.4/5GHz band AC750 router, based on MediaTek MT7620A.

Specifications:
- SoC: MT7620A
- RAM: DDR2 64MB
- Flash: SPI NOR 16MB
- WiFi:
  - 2.4GHz: SoC internal
  - 5GHz: MT7610EN
- Ethernet: 5x 10/100/1000Mbps
  - Switch: MT7530BU
- UART:
  - J2: 3.3V, RX, TX, GND (3.3V is the square pad) / 57600 8N1

MAC addresses in factory partition:
0x0004: LAN, WiFi 2.4GHz (label_mac-6)
0x0028: not used (label_mac-1)
0x002e: WAN (label_mac)
0x8004: WiFi 5GHz (label_mac+2)

Installation via web interface:
1.  Flash **initramfs** image through the stock web interface.
2.  Boot into OpenWrt and perform sysupgrade with sysupgrade image.

Revert to stock firmware:
1.  Perform sysupgrade with stock image.

Reviewed-by: Pawel Dembicki <paweldembicki@gmail.com>
Signed-off-by: Sungbo Eo <mans0n@gorani.run>

target/linux/ramips/mt7620/base-files/etc/board.d/02_network

@@ -170,6 +170,7 @@ ramips_setup_interfaces()
 			"1:lan:4" "2:lan:3" "4:lan:2" "5:lan:1" "0:wan" "6@eth0"
 		;;
 	linksys,e1700|\
+	netis,wf2770|\
 	ralink,mt7620a-mt7530-evb)
 		ucidef_add_switch "switch0"
 		ucidef_add_switch_attr "switch0" "enable" "false"
@@ -338,6 +339,10 @@ ramips_setup_macs()
 	linksys,e1700)
 		wan_mac=$(mtd_get_mac_ascii config WAN_MAC_ADDR)
 		;;
+	netis,wf2770)
+		wan_mac=$(mtd_get_mac_binary factory 0x2e)
+		label_mac=$wan_mac
+		;;
 	tplink,archer-c2-v1|\
 	tplink,archer-c20-v1|\
 	tplink,archer-c20i|\