mwifiex: handle start AP error paths correctly

It's been observed that even if firmware returns an error
for a configuration command, we go ahead and start AP.

This patch changes the command type from async to sync
so that threads waits for command response and return
failure start AP.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>