* ath79: add support for TP-Link TL-WR882N/WR885N/WR886N

This adds support for the various clones of the TL-WR885N recently
supported  ("ath79: add support for TP-Link TL-WR885N v1"):

- tplink,tl-wr882n-v1
- tplink,tl-wr882n-v2
- tplink,tl-wr882n-v3
- tplink,tl-wr885n-v1
- tplink,tl-wr885n-v2
- tplink,tl-wr886n-v2
- tplink,tl-wr886n-v3
- tplink,tl-wr886n-v4
- tplink,tl-wr886n-v5
- tplink,tl-wr886n-v6
- tplink,tl-wr886n-v7

These devices are cloned in ar71xx. All models added in this patch are the same hardware CPU

WR885n V2 was tested.

Specifications:
- SOC: Qualcomm Atheros TP9343-AL3A
- CPU: 750MHz
- Flash: 2 MiB (AH1446 25Q16BS1G E5N102)
- RAM: 16 MiB (Zentel A3S28D40JTP-50)
- WLAN: Qualcomm Atheros TP9343 450Mbps
- Ethernet: Atheros AR8228/AR8229  4 port (100M)

添加TP9343芯片的路由器型号支持，TL-WR882N/WR885N/WR886N系列

* ath79: add support for MerCury MW4530R v1

重新添加水星MW4530R路由器支持