mwifiex: update IEs after AP has started

This patch moves IE management routine to end of start_ap handler.
IEs now would be updated after AP has started.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Qingshui Gao <gaoqs@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>