ath79: add support for TP-Link RE455 v1

TP-Link RE455 v1 is a dual band router/range-extender based on
Qualcomm/Atheros QCA9563 + QCA9880.

This device is nearly identical to RE450 v3

Specification:

- 775 MHz CPU
- 64 MB of RAM (DDR2)
- 8 MB of FLASH (SPI NOR)
- 3T3R 2.4 GHz
- 3T3R 5 GHz
- 1x 10/100/1000 Mbps Ethernet (AR8033 PHY)
- 7x LED, 4x button
- UART header on PCB[1]

Flash instruction:
Apply factory image in OEM firmware web-gui.

[1] Didn't work, probably need to short unpopulated resistor R64
    and R69 as RE450v3

Signed-off-by: Roberto Valentini <valantin89@gmail.com>

target/linux/ath79/generic/base-files/etc/board.d/01_leds

@@ -352,7 +352,8 @@ tplink,tl-wr902ac-v1)
 tplink,re355-v1|\
 tplink,re450-v1|\
 tplink,re450-v2|\
-tplink,re450-v3)
+tplink,re450-v3|\
+tplink,re455-v1)
 	ucidef_set_led_netdev "lan_data" "LAN Data" "green:lan_data" "eth0" "tx rx"
 	ucidef_set_led_netdev "lan_link" "LAN Link" "green:lan_link" "eth0" "link"
 	;;

target/linux/ath79/generic/base-files/etc/board.d/02_network

@@ -70,6 +70,7 @@ ath79_setup_interfaces()
 	tplink,re450-v1|\
 	tplink,re450-v2|\
 	tplink,re450-v3|\
+	tplink,re455-v1|\
 	tplink,tl-wr902ac-v1|\
 	ubnt,bullet-ac|\
 	ubnt,bullet-m-ar7240|\