ieee802154: move headers out of extra directory

include/net/ieee802154/af_ieee802154.h (and others) naming seems to be too long
and redundant. Drop one level of subdirectories.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
diff --git a/net/ieee802154/af_ieee802154.c b/net/ieee802154/af_ieee802154.c
index 3bb6bdb..69c8d92 100644
--- a/net/ieee802154/af_ieee802154.c
+++ b/net/ieee802154/af_ieee802154.c
@@ -34,8 +34,8 @@
 #include <net/tcp_states.h>
 #include <net/route.h>
 
-#include <net/ieee802154/af_ieee802154.h>
-#include <net/ieee802154/netdevice.h>
+#include <net/af_ieee802154.h>
+#include <net/ieee802154_netdev.h>
 
 #include "af802154.h"