XM/XenAPI: Add blktap support when creating domains by xm through Xen API.

Signed-off-by: Yosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>

tools/python/xen/xm/xenapi_create.py

@@ -509,7 +509,7 @@ class sxp2xml:
                    if len(child) > 0 and child[0] == "device"]
                    
         vbds_sxp = map(lambda x: x[1], [device for device in devices
-                                        if device[1][0] == "vbd"])
+                                        if device[1][0] in ("vbd", "tap")])
 
         vifs_sxp = map(lambda x: x[1], [device for device in devices
                                         if device[1][0] == "vif"])