mac802154: use new nl802154 iftype types

This patch replace the depracted IEEE802154_DEV to the new introduced
NL802154_IFTYPE_NODE types. There is a backwards compatibility to have
the identical types for both enum definitions. Also remove some inlcude
issue with "linux/nl802154.h", because the export nl_policy inside this
header it was always necessary to have an include of "net/rtnetlink.h"
before. The reason for this is more complicated. Nevertheless we removed
this now, because "linux/nl802154.h" is the depracted netlink interface.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>