wl12xx: call wl12xx_cmd_set_peer_state() in AP mode

After adding a station, call wl12xx_cmd_set_peer_state().
This is required for 11n support.

Change wl12xx_cmd_set_peer_state() prototype to get hlid
as param.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>