No 5GHz Wi-Fi on HC5761

My device is hiwifi HC5761 and I've flashed the official 17.01.4 firmware but there's no entry to 5GHz and can't enable it, is there any way to enable 5GHz Wi-Fi? I can only use 2.4GHz Wi-Fi right now.

SSH in to the router and run the following...

dmesg | grep 'wlan'

Post the results.