iwlwifi: Led blinking counting both tx and rx

For controlling led blinking, counting both tx and rx data traffic; this
will be able to handle traffic in either direction

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>