ar71xx-tiny: add TP-Link TL-WA701N/ND v2 again

It seems the device was lost during the OpenWrt -> LEDE migration.

targets/ar71xx-tiny

@@ -10,6 +10,7 @@ device d-link-dir-615-rev-c1 dir-615-c1 DIR615C1
 # TP-Link
 
 device tp-link-tl-wa701n-nd-v1 tl-wa701nd-v1
+device tp-link-tl-wa701n-nd-v2 tl-wa701nd-v2
 
 device tp-link-tl-wa7210n-v2 tl-wa7210n-v2
 device tp-link-tl-wa7510n-v1 tl-wa7510n