All 802.11n and 802.11ac access points  have WMM enabled in
their default configuration and cannot be disabled. There are also no
adjustable QoS parameters. If you don't want your access point to
support WMM, change the wireless mode to 802.11b/g or g only. 

Keep in mind that WMM (Wi-Fi Multimedia) prioritizes network traffic
according to four access categories: voice, video, best effort, and
background.