Staging: batman-adv: multiple mesh clouds

This patch removes all remaining global variables and includes the
necessary bits into the bat_priv structure. It is the last
remaining piece to allow multiple concurrent mesh clouds on the
same device.
A few global variables have been rendered obsolete during the process
and have been removed entirely.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>