ath10k: advertise force AP scan feature

Results obtained from scan can be used for spectrum management by
doing something like building information of preferred channel
lists and sharing them with stations around. It is to be noted
that traffic to the connected stations would be affected during
the scan.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>