stdlib: Use near atomics in the CHI component nodes

This is a temporary solution to fix daily tests. We could revert
to the default (policy_type = 1) once the problem is properly
fixed

Change-Id: Ia80af9a7d84d5c777ddeb441110a91a1680c1030
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

src/python/gem5/components/cachehierarchies/chi/nodes/abstract_node.py

@@ -85,6 +85,9 @@ class AbstractNode(Cache_Controller):
         # Use 32-byte channels (two flits per message)
         self.data_channel_size = 32
 
+        # Use near atomics (see: https://github.com/gem5/gem5/issues/449)
+        self.policy_type = 0
+
         self.connectQueues(network)
 
     def getBlockSizeBits(self):