wireless: unify QoS control field definitions

Move all that mac80211 has into the generic
ieee80211.h header file and use them. At the
same time move them from mask+shift to just
bits and rename them for consistent names.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>