iwlwifi: mvm: treat netdetect wake up separately

When the device wakes up due to netdetect, we need to query different
things from the firmware than when it wakes up with a normal WoWLAN.
To make this easier, separate the netdetect wake up handling from the
rest.  For now, we don't send netdetect as a wake up reason, treating
it as a non-wireless wake up.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>