iwlwifi: dbg: add debug host notification (DHN) time point

This enables to listen only to DHN time point without monitoring
every rx packet from FW.

Also fix a typo NOTIFOCATION->NOTIFICATION in enum declaration.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200930191738.435fa657a937.I1a36badd4ceecefcdfb47eaacf26c08a4bbd1b08@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>