cpu-o3: Removed "Aggressive" SMT scheduling option

A comment claimed this to be different from "oldestReady", when in fact
it was not. Removed it for clarity.

Change-Id: Ic66ee9974ddc8d7a01929afabb601473b7ea23ad
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46939
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/cpu/o3/O3CPU.py

@@ -52,7 +52,7 @@ class SMTQueuePolicy(ScopedEnum):
     vals = [ 'Dynamic', 'Partitioned', 'Threshold' ]
 
 class CommitPolicy(ScopedEnum):
-    vals = [ 'Aggressive', 'RoundRobin', 'OldestReady' ]
+    vals = [ 'RoundRobin', 'OldestReady' ]
 
 class O3CPU(BaseCPU):
     type = 'O3CPU'

src/cpu/o3/commit.cc

@@ -1444,13 +1444,6 @@ Commit::getCommittingThread()
 {
     if (numThreads > 1) {
         switch (commitPolicy) {
-
-          case CommitPolicy::Aggressive:
-            //If Policy is Aggressive, commit will call
-            //this function multiple times per
-            //cycle
-            return oldestReady();
-
           case CommitPolicy::RoundRobin:
             return roundRobin();