ar71xx: add support for Wallys DR531

Wallys DR531 is based on Qualcomm Atheros QCA9531 v2.
Short specification:

- 550/400/200 MHz (CPU/DDR/AHB)
- 2x 10/100 Mbps Ethernet
- 64 MB of RAM (DDR2)
- 8 MB of FLASH
- 2T2R 2.4 GHz with external PA (SE2576L), up to 30 dBm
- 2x MMCX connectors
- mini-PCIe connector with PCIe/USB buses and SIM slot
- 7x LED, 1x button, 1x optional buzzer
- UART, (E)JTAG and LED headers

Default configuration:

- WAN on eth1 (RJ45 near DC jack)
- LAN on eth0 (RJ45 near button)
- S4 LED set to be status LED
- all LEDs configurable form user space
- button configured for reset

Flash instruction (do it under U-Boot, using UART):

1. tftp 0x80060000 lede-ar71xx-generic-dr531-squashfs-sysupgrade.bin
2. erase 0x9f050000 +$filesize
3. cp.b $fileaddr 0x9f050000 $filesize
4. setenv bootcmd "bootm 0x9f050000"
5. saveenv && reset

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

target/linux/ar71xx/base-files/etc/board.d/01_leds

@@ -156,6 +156,11 @@ db120)
 	ucidef_set_led_usbdev "usb" "USB" "db120:green:usb" "1-1"
 	;;
 
+dr531)
+	ucidef_set_led_netdev "lan" "LAN" "dr531:green:lan" "eth0"
+	ucidef_set_led_netdev "wan" "WAN" "dr531:green:wan" "eth1"
+	;;
+
 dragino2)
 	ucidef_set_led_wlan "wlan" "WLAN" "dragino2:red:wlan" "phy0tpt"
 	ucidef_set_led_netdev "lan" "LAN" "dragino2:red:lan" "eth0"

target/linux/ar71xx/base-files/etc/board.d/02_network

@@ -426,6 +426,7 @@ unifiac-pro)
 		"0@eth0" "2:lan" "3:wan"
 	;;
 
+dr531 |\
 wpj531)
 	ucidef_set_interfaces_lan_wan "eth0" "eth1"
 	;;

target/linux/ar71xx/base-files/etc/diag.sh

@@ -113,6 +113,9 @@ get_status_led() {
 	dr344)
 		status_led="dr344:green:status"
 		;;
+	dr531)
+		status_led="dr531:green:sig4"
+		;;
 	dragino2)
 		status_led="dragino2:red:system"
 		;;