iwlwifi: clean up HW RF-kill state machine and restarts

This patch cleans up HW RF-kill state machine.

Signed-off-by: Mohamed Abbas <mohamed.abbas@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>