iwlwifi: add new firmware for 6005 devices

New iwlwifi-6000g2a-5.ucode for 6005 series devices
version: 17.168.5.1

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

WHENCE

@@ -671,6 +671,9 @@ Info: v9.193.4.1
 File: iwlwifi-6050-4.ucode
 Info: v9.201.4.1
 
+File: iwlwifi-6000g2a-5.ucode
+Info: v17.168.5.1
+
 Licence: Redistributable. See LICENCE.iwlwifi_firmware for details
 
 Also available from http://intellinuxwireless.org/?n=Downloads