mac802154: fix duplicate #include headers

The commit e6278d92 ("mac802154: use header operations to
create/parse headers") included the header

		net/ieee802154_netdev.h

which had been included by the commit b70ab2e8 ("ieee802154:
enforce consistent endianness in the 802.15.4 stack"). Fix this
duplicate #include by deleting the latter one as the required header
has already been in place.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Cc: linux-zigbee-devel@lists.sourceforge.net
Signed-off-by: David S. Miller <davem@davemloft.net>