wifi: rtw88: Enable the new RTL8821AU/RTL8812AU drivers

wifi: rtw88: Enable the new RTL8821AU/RTL8812AU drivers

These are older Wifi 5 chips. RTL8821AU is 1x1, with or without
Bluetooth. RTL8812AU is 2x2, without Bluetooth.

Beamforming is not implemented. It looks like these chips need a
different implementation than what is in bf.c.

Speed tests with RTL8821AU: 137 Mbps download, 144 Mbps upload.
Speed tests with RTL8812AU: 344 Mbps download, 387 Mbps upload.

Station mode and AP mode were tested.

Bluetooth coexistence works. I used my Bluetooth headphones for
several days, listening to music and watching videos. There is only
a problem with the wifi speeds with one router:

With ISP's HG6544C router:
Official driver: 3/5 Mbps.
rtw88: a bit more, but not steady at all. Not enough to watch a 1080p
Youtube video.

With my D-Link Eagle R32 router running Openwrt, on the same channel:
Official driver: 6/10 Mbps.
rtw88: download starts around 30, climbs to 50 / upload is 10 Mbps.
I can watch a 1080p Youtube video.

The music doesn't cut out during any speed tests.

I also tested transferring files to and from my phone. I don't have
other types of Bluetooth devices to test.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/0b8e8093-8103-4999-86bf-0055ec52ea64@gmail.com