iwlwifi: bump FW API to 55 for AX devices

Start supporting API version 55 for AX devices.  We skipped 54 because
it won't be published.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200424182644.5b4628e18203.I626d3b19d84214a83cd92dc4ddf291903b0983aa@changeid

drivers/net/wireless/intel/iwlwifi/cfg/22000.c

@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2015-2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2019 Intel Corporation
+ * Copyright (C) 2018-2020 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -20,7 +20,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2015-2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2019 Intel Corporation
+ * Copyright (C) 2018-2020 Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -57,7 +57,7 @@
 #include "iwl-prph.h"
 
 /* Highest firmware API version supported */
-#define IWL_22000_UCODE_API_MAX	53
+#define IWL_22000_UCODE_API_MAX	55
 
 /* Lowest firmware API version supported */
 #define IWL_22000_UCODE_API_MIN	39