iwlwifi: add support for SnJ with Jf devices

Add support for SnJ devices with Jf and a workaround for some cases
where the devices erroneously show as QnJ devices.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210205110447.ae6ed654e557.Ic11ed4df410328359b6a2c997456692901d99468@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>