iwlwifi: jiffies based tx queues watchdog

This patch replace monitor/recover timer by watchdog based on time
stamp. New code allow to discover hangs more precisely.

Timeout values are currently doubled monitoring period values of
previous timer. This have to be tuned based of firmware timing
capabilities.

Tested on 3945, 4965, 5300, 6300.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>