iwlwifi: nvm: fix VHT capability antenna-dependent fields

As the antenna dependent fields depend on the firmware file and not
the NVM, use those fields in the VHT capability creation.

Additionally, fix the STBC and antenna pattern consistency fields.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>