wl12xx: Configure AP on BSS info change

Configure AP-specific beacon and probe response templates.
Start the AP when beaconing is enabled.

The wl1271_bss_info_changed() function has been split into AP/STA
specific handlers.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Reviewed-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>