auxbus: New aux_bus_realize(), pairing with aux_bus_init()

aux_bus_init() encapsulates the creation of an aux-bus and its
aux-to-i2c-bridge device.

Create aux_bus_realize() to similarly encapsulate their realization.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-33-armbru@redhat.com>
3 files changed