ramips: add support for TP-Link TL-WR842N v5

TP-Link TL-WR842N v5 are simple N300 router with 5-port FE switch and
non-detachable antennas. Its very similar to TP-Link TL-MR3420 V5.

Specification:

- MT7628N/N (580 MHz)
- 64 MB of RAM (DDR2)
- 8 MB of FLASH
- 2T2R 2.4 GHz
- 5x 10/100 Mbps Ethernet
- 2x external, non-detachable antennas
- USB 2.0 Port
- UART (J1) header on PCB (115200 8n1)
- 7x LED, 2x button, power input switch

Flash instruction:

The only way to flash OpenWrt image in wr842nv5 is to use
tftp recovery mode in U-Boot:

1. Configure PC with static IP 192.168.0.225/24 and tftp server.
2. Rename "lede-ramips-mt7628-tplink_tl-wr842n-v5-squashfs-tftp-recovery.bin"
   to "tp_recovery.bin" and place it in tftp server directory.
3. Connect PC with one of LAN ports, press the reset button, power up
   the router and keep button pressed for around 6-7 seconds, until
   device starts downloading the file.
4. Router will download file from server, write it to flash and reboot.

Signed-off-by: Maxim Anisimov <maxim.anisimov.ua@gmail.com>

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

@@ -414,7 +414,8 @@ tplink,c50-v3)
 	ucidef_set_led_wlan "wlan2g" "wlan2g" "$boardname:green:wlan2g" "phy0tpt"
 	ucidef_set_led_wlan "wlan5g" "wlan5g" "$boardname:green:wlan5g" "phy1tpt"
 	;;
-tplink,tl-mr3420-v5)
+tplink,tl-mr3420-v5|\
+tplink,tl-wr842n-v5)
 	set_usb_led "$boardname:green:usb"
 	ucidef_set_led_wlan "wlan2g" "wlan2g" "$boardname:green:wlan" "phy0tpt"
 	ucidef_set_led_switch "lan" "lan" "$boardname:green:lan" "switch0" "0x1e"

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

@@ -205,6 +205,7 @@ ramips_setup_interfaces()
 	tplink,c20-v4|\
 	tplink,c50-v3|\
 	tplink,tl-mr3420-v5|\
+	tplink,tl-wr842n-v5|\
 	tl-wr840n-v4|\
 	tl-wr840n-v5|\
 	tl-wr841n-v13|\

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

@@ -42,6 +42,7 @@ get_status_led() {
 	tplink,c20-v4|\
 	tplink,c50-v3|\
 	tplink,tl-mr3420-v5|\
+	tplink,tl-wr842n-v5|\
 	tplink,tl-wr902ac-v3|\
 	tl-wr840n-v4|\
 	tl-wr840n-v5|\

target/linux/ramips/base-files/lib/upgrade/platform.sh

@@ -255,6 +255,7 @@ platform_check_image() {
 	tplink,c20-v4|\
 	tplink,c50-v3|\
 	tplink,tl-mr3420-v5|\
+	tplink,tl-wr842n-v5|\
 	tplink,tl-wr902ac-v3|\
 	tl-wr840n-v4|\
 	tl-wr840n-v5|\