ath6kl: Add WSC IE on the associate message

For some WPS test items, such as item "5.1.14"
STAUT must include the WSC IE in the 802.11 Association Request frame.
Therefore, add the corresponding IE in association message.

Signed-off-by: Kevin Fang <kevin.fang@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>