ath6kl: Fix bug in setting dot11_auth_mode in AP mode

OPEN_AUTH is passed as dot11_auth_mode by default, this would
affect the AP mode when configured with shared authentication
type. Assign appropriate auth type to fix this from driver.
A patch in wpa_supplicant (wpa_supplicant: Set configured auth_algs)
is also needed to fix this.

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