ath9k: Add Dell Wireless 1802 with wowlan capability

Add the Dell Wireless 1802 card as an AR9462 in the ath9k pci list.
Note that the wowlan feature is supported and has been tested
successfully.

Signed-off by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>