cpu: Add HtmCpu DebugFlag

JIRA: https://gem5.atlassian.net/browse/GEM5-587

Change-Id: Id4b86b8964bc64bce1d2e4af941217eb114f3cc4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30320
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/cpu/SConscript b/src/cpu/SConscript
index dea7e92..194631a 100644
--- a/src/cpu/SConscript
+++ b/src/cpu/SConscript
@@ -1,5 +1,17 @@
 # -*- mode:python -*-
 
+# Copyright (c) 2020 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
 # Copyright (c) 2006 The Regents of The University of Michigan
 # All rights reserved.
 #
@@ -51,6 +63,7 @@
 DebugFlag('ExecAsid', 'Format: Include ASID in trace')
 DebugFlag('ExecFlags', 'Format: Include instruction flags in trace')
 DebugFlag('Fetch')
+DebugFlag('HtmCpu', 'Hardware Transactional Memory (CPU side)')
 DebugFlag('IntrControl')
 DebugFlag('O3PipeView')
 DebugFlag('PCEvent')