iwlwifi: fix rf_kill state inconsistent during suspend and resume

The patch fixes the STATUS_RF_KILL_HW state is not cleared problem if the
device goes to suspend when the rf_kill switch is enabled. The bug causes
the driver always thinks the rf_kill switch is enabled (although it is
disabled) after resume.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>