This lets 'iw phy phy0 info' report antennas for
the radio device:

...
	Available Antennas: TX 0x2 RX 0x2
	Configured Antennas: TX 0x2 RX 0x2
...
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NKalle Valo <kvalo@qca.qualcomm.com>