modules: hostap: Fix WPA supplicant debug logging

Despite having higher log buffer sizes the log messages are being
dropped due to high rate (and longer messages) as hostap debugging is
very verbose, so, use "immediate" logging by default. As hostap is only
for control path this will not have impact on timing.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>