hw/m68k: add Nubus support

This patch adds basic support for the NuBus bus. This is used by 680x0
Macintosh.

Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20191026164546.30020-8-laurent@vivier.eu>
diff --git a/MAINTAINERS b/MAINTAINERS
index 3ce8d10..7892ab5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -921,7 +921,9 @@
 M: Laurent Vivier <laurent@vivier.eu>
 S: Maintained
 F: hw/misc/mac_via.c
+F: hw/nubus/*
 F: include/hw/misc/mac_via.h
+F: include/hw/nubus/*
 
 MicroBlaze Machines
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