ipq806x: add support for TP-Link Talon AD7200

[Ansuel Smith]

>
> From: Gary Cooper <gaco at mail2tor.com>
>
> Device hardware: https://deviwiki.com/wiki/TP-LINK_AD7200_(Talon)
>
> The Talon AD7200 is basically an Archer C2600 with larger flash, a third PCIe lane and an 802.11ad radio. It comes in a different housing reminiscent of the Archers C3200 and C5400.
>
>
> Specifications
> --------------
>
>   - IPQ8064 dual-core 1400MHz
>   - QCA9988 2.4GHz WiFi
>   - QCA9888 5GHz WiFi
>   - QCA9500 60GHz WiFi
>   - 256MiB SPI Flash
>   - 512MiB RAM
>   - 5 GBit Ports (QCA8337)
>
> Installation
> ------------
>
> Installation is possible from the OEM web interface.
> Sysupgrade is possible.
> TFTP recovery is possible.
>   - Image: AD7200_1.0_tp_recovery.bin
>
> Notes
>   - This will be the first 802.11ad device supported by mainline.

Incredible that they chose ipq8064 for wifi ad and not the more recent soc...