[MAC80211]: rename ieee80211_cfg.c to cfg.c

It's just painful to have the extra ieee80211_ prefix.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NMichael Wu <flamingice@sourmilk.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/mac80211/Makefile

@@ -17,7 +17,7 @@ mac80211-objs := \
 	regdomain.o \
 	tkip.o \
 	aes_ccm.o \
-	ieee80211_cfg.o \
+	cfg.o \
 	rx.o \
 	tx.o \
 	key.o \