iwlwifi: add option to disalbe LED

Led has no use for some platform.
Add additional module parameter option to disable LED

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-shared.h b/drivers/net/wireless/iwlwifi/iwl-shared.h
index e406d49..04975b7 100644
--- a/drivers/net/wireless/iwlwifi/iwl-shared.h
+++ b/drivers/net/wireless/iwlwifi/iwl-shared.h
@@ -264,11 +264,13 @@
  *			LED ON  = RF ON
  *			LED OFF = RF OFF
  *    IWL_LED_BLINK:    adjust led blink rate based on blink table
+ *    IWL_LED_DISABLE:	led disabled
  */
 enum iwl_led_mode {
 	IWL_LED_DEFAULT,
 	IWL_LED_RF_STATE,
 	IWL_LED_BLINK,
+	IWL_LED_DISABLE,
 };
 
 /**