ath6kl: Fix possible unaligned memory access in ath6kl_get_rsn_capab()

alignment is not taken care in accessing pairwise cipher and AKM suite
count which are parsed from rsn ie. Fix this alignment issue.

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>