mem-ruby: Fix deadlock in GPU_VIPER when issuing atomic requests

When a compute unit issues several requests to the same line,
the requests wait in the L2 if it is a writeback cache. If the line is
invalid initially and the first request is atomic in nature, the L2
cache issues a request to main memory. On data return, the cache line
transitions to M but doesn't wake up the other requests, resulting in
a deadlock. This commit adds a wakeup call on data return for atomics
and fixes potential deadlocks.

Change-Id: I8200ce6e77da7c8b4db285c0cc8b8ca0dfa7d720

src/mem/ruby/protocol/GPU_VIPER-TCC.sm

@@ -1299,6 +1299,7 @@ machine(MachineType:TCC, "TCC Cache")
     wardb_writeAtomicResponseDirtyBytes;
     pa_performAtomic;
     baplr_sendBypassedAtomicPerformedLocallyResponse;
+    wada_wakeUpAllDependentsAddr;
     dt_deallocateTBE;
     pr_popResponseQueue;
   }