ath9k_htc: add device ID for Toshiba WLM-20U2/GN-1080

This device is available under different marketing names:
WLM-20U2 - Wireless USB Dongle for Toshiba TVs
GN-1080 - Wireless LAN Module for Toshiba MFPs.

Signed-off-by: Alexander Tsoy <alexander@tsoy.me>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>