mwl8k: Add/Del self entry for AP interface only

Add and delete self entry in the firmware sta database
for AP interface only. We do not need such an entry for
STA interface.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>