iwlagn: report correct temperature for WiFi/BT devices.

The temperature reported by 'cat /sys/class/net/wlan?/device/temperature'
is incorrect for devices with BT capability.  Report the value from the
correct statistics structure.  Tested with 130, 100, 6205 and 5300.

Signed-off-by: Don Fry <donald.h.fry@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>