mac80211: move spectrum management code out

Like the HT code, this doesn't depend on the STA-mode implementation
and can be handled entirely independently. There's only stub code
for now, but when it gets filled having it in its own file will be
beneficial.

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

net/mac80211/Makefile

@@ -17,6 +17,7 @@ mac80211-y := \
 	aes_ccm.o \
 	cfg.o \
 	rx.o \
+	spectmgmt.o \
 	tx.o \
 	key.o \
 	util.o \