m68k/mac: Mark Mac IIsi ADB driver BROKEN

As reported by Finn Thain, the Mac IIsi ADB driver should be disabled
because it will crash.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

drivers/macintosh/Kconfig

@@ -32,7 +32,7 @@ config ADB_MACII
 
 config ADB_MACIISI
 	bool "Include Mac IIsi ADB driver"
-	depends on ADB && MAC
+	depends on ADB && MAC && BROKEN
 	help
 	  Say Y here if want your kernel to support Macintosh systems that use
 	  the Mac IIsi style ADB.  This includes the IIsi, IIvi, IIvx, Classic