This is dead code, nothing uses the IWL_DEVICE_22560 macro and
thus nothing every uses IWL_DEVICE_FAMILY_22560. Remove it all.

While at it, remove some code and definitions used only in this
case, and clean up some comments/names that still refer to it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>