batman-adv: make struct batadv_orig_node algorithm agnostic

some of the struct batadv_orig_node members are B.A.T.M.A.N. IV
specific and therefore they are moved in a algorithm specific
substruct in order to make batadv_orig_node routing algorithm
agnostic

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>