mac802154: fix flags BIT definitions order

This patch fixes commits ("mac802154: cleanup ieee802154 hardware flags")
bcbfd207 and ("mac802154: cleanup address
filtering flags") 6b70a43c by starting
the flags definitions at BIT(0) which is same like the previous behaviour.

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