batman-adv: remove ogm_emit and ogm_schedule API calls

The ogm_emit and ogm_schedule API calls were rather tight to the
B.A.T.M.A.N. IV logic and therefore rather difficult to use
with other algorithm implementations.

Remove such calls and move the surrounding logic into the
B.A.T.M.A.N. IV specific code.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>