staging: vme: remove vme_add_bus() and vme_remove_bus()

The functions vme_add_bus() and vme_remove_bus() were only being used
in the vme_register_bridge() and vme_unregister_bridge() functions
respectively. This patch gets rid of them and moves their code to
vme_register_bridge() and vme_unregister_bridge().

Signed-off-by: Manohar Vanga <manohar.vanga@cern.ch>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>