[qemu] Add switch to control whether acpi bridge is enabled.

Signed-off-by: Winston Wang <winston.l.wang@intel.com>

tools/python/xen/sv/CreateDomain.py

@@ -180,6 +180,7 @@ class CreateFinish( Sheet ):
         vals.ssidref = -1
         vals.bootloader = None
         vals.usb = []
+        vals.acpi = []
         
         #setup vifs
         

tools/python/xen/xend/image.py

@@ -251,7 +251,7 @@ class HVMImageHandler(ImageHandler):
     def parseDeviceModelArgs(self, imageConfig, deviceConfig):
         dmargs = [ 'boot', 'fda', 'fdb', 'soundhw',
                    'localtime', 'serial', 'stdvga', 'isa', 'vcpus',
-		   'usb', 'usbdevice']
+		   'acpi', 'usb', 'usbdevice']
         ret = []
         for a in dmargs:
             v = sxp.child_value(imageConfig, a)