Make the name of CPUInfo type more friendly

Since code is 'json.loads(value)', it's more firendly
to tell users the expected format should be JSON string

Change-Id: Ib79fbb36e149780d47b758763c4ac13aae552f1f

blazar/api/v2/controllers/types.py

@@ -73,7 +73,7 @@ class CPUInfo(wtypes.UserType):
     """A type for matching CPU info from hypervisors."""
 
     basetype = wtypes.text
-    name = 'cpuinfo'
+    name = 'cpuinfo as JSON formated str'
 
     @staticmethod
     def validate(value):