ramips: add support for ipTIME A104ns

ipTIME A104ns is a 2.4/5GHz band AC750 router, based on MediaTek MT7620A.

Specifications:
- SoC: MT7620A
- RAM: DDR2 64MB
- Flash: SPI NOR 8MB
- WiFi:
  - 2.4GHz: SoC internal
  - 5GHz: MT7610EN
- Ethernet: 5x 10/100Mbps
  - Switch: SoC internal
- USB: 1x 2.0
- UART:
  - J2: 3.3V, TX, RX, GND (3.3V is the square pad) / 57600 8N1

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.

In contrast to to-be-supported A1004ns, the A104ns has no usable
value in 0x1fc40 (uboot), so wan_mac needs to be calculated.
Also note that GPIOs for the LEDs really are inverted compared to
the A1004ns.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>
[moved state_default to device DTS, reordered properties in wmac,
added comment about wan_mac and LED GPIOs]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

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

@@ -139,6 +139,10 @@ ramips_setup_interfaces()
 		ucidef_add_switch "switch1" \
 			"1:lan:4" "2:lan:3" "3:lan:2" "4:lan:1" "0:wan" "6@eth0"
 		;;
+	iptime,a104ns)
+		ucidef_add_switch "switch0" \
+			"1:lan:4" "2:lan:3" "3:lan:2" "4:lan:1" "0:wan" "6@eth0"
+		;;
 	kingston,mlw221)
 		ucidef_set_interface_lan "eth0.2"
 		;;
@@ -301,6 +305,9 @@ ramips_setup_macs()
 	iodata,wn-ac733gr3)
 		wan_mac=$(mtd_get_mac_ascii u-boot-env wanaddr)
 		;;
+	iptime,a104ns)
+		wan_mac=$(macaddr_add "$(mtd_get_mac_binary u-boot 0x1fc20)" 2)
+		;;
 	lenovo,newifi-y1|\
 	lenovo,newifi-y1s|\
 	ohyeah,oy-0001|\