iwlwifi: bump FW API to 72 for AX devices

Start supporting API version 72 for AX devices.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20220304131517.8de72a8ea67f.I66681363afeb34c619379a5989090264fe6b5f2a@changeid


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