ath10k: don't advertise IBSS iftype for 10.x

The 10.x firmware does not support IBSS mode at
all. It can't beacon and it crashes when trying to
scan.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>