iwlwifi: bump FW API to 67 for AX devices

Start supporting API version 67 for AX devices.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211024181719.3c0af5832d23.I7c18858604b72bc15cf2047a91531e4aa7c0527a@changeid


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