Mark AP disabled if initialization steps fail

Mark AP disabled if initialization steps fail

Previously, some of the last initialization steps could fail without
clearly marking the interface disabled. For example, configuring the
channel to the driver could fail, but hostapd would not clearly identify
as the interface not being in functional state apart from not moving it
to the ENABLED state. Send an AP-DISABLED event and mark interface state
DISABLED if such a setup operation fails.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>