iwlwifi: add value and range define for link quality command

Instead of hardcoding the link quality parameters inside the functions,
adding #define in iwl-commands.h to shared by different functions.
Also include the valid range for number of link quality parameters.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-commands.h b/drivers/net/wireless/iwlwifi/iwl-commands.h
index b3229f2..c87033b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-commands.h
+++ b/drivers/net/wireless/iwlwifi/iwl-commands.h
@@ -1913,6 +1913,18 @@
 	u8 start_rate_index[LINK_QUAL_AC_NUM];
 } __attribute__ ((packed));
 
+#define LINK_QUAL_AGG_TIME_LIMIT_DEF	(4000) /* 4 milliseconds */
+#define LINK_QUAL_AGG_TIME_LIMIT_MAX	(65535)
+#define LINK_QUAL_AGG_TIME_LIMIT_MIN	(0)
+
+#define LINK_QUAL_AGG_DISABLE_START_DEF	(3)
+#define LINK_QUAL_AGG_DISABLE_START_MAX	(255)
+#define LINK_QUAL_AGG_DISABLE_START_MIN	(0)
+
+#define LINK_QUAL_AGG_FRAME_LIMIT_DEF	(31)
+#define LINK_QUAL_AGG_FRAME_LIMIT_MAX	(64)
+#define LINK_QUAL_AGG_FRAME_LIMIT_MIN	(0)
+
 /**
  * struct iwl_link_qual_agg_params
  *