Second set of iwlwifi fixes for 4.14
* Fix support for 3168 device series;
* Fix a potential crash when using FW debugging recording;
* Improve channel flags parsing to avoid warnings on too long traces;
* Return -ENODATA when the temperature is not available, since the
-EIO we were returning was causing fatal errors in userspace;
* Avoid printing too many messages in dmesg when using monitor mode,
since this can become very noisy and completely flood the logs;