iwlagn: remove priv dereferences from the transport layer

Another round of clean up on the transport layer.
Define a wrapper around wiphy_rfkill_set_hw_state to prevent the
transport layer from accessing priv->hw.
Also move wait_command_queue to the transport layer.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>