iwlwifi: remove frame dropping

With some of the new code in mac80211, public action
frames can be exchanged as non-injected frames even
while not associated.

Aside from that, dropping frames here is pointless
since we do deal with arbitrary frames that were
injected already, so let mac80211 make the decision
about which frames to allow or not.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>