iwlwifi: take valid ant for HT caps from TLV

I forgot to take them from TLV and took them from the NVM
instead.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>