iwlwifi: Add led support

iwlwifi: Add led support

This patch add LEDS support to 3965 and 4965 drivers. It is based on
led trigger and class. For our drivers we needed to avoid two things.
1- We receive led trigger on/off on each Rx\Tx frame. In our driver
    we can not call led command like that. In this driver once driver
    receive a start of traffic it call the led command to start blinking
    then we count all bytes of Tx and Rx frame, after two second we count the
    blink rate of last two second then id blink rate changed we call the led
     commands
2- Since we can call led command very often, we make sure we call the
    led command after we receive the statistics notification so
    we don't need to wake up the ucode id it is in sleep state.
    This patch was tested with 4965 and 3945.

Signed-off-by: Mohamed Abbas <mabbas@linux.intel.com>
Signed-off-by: Ian Schram<ischram@telenet.be>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>