Use goyt with 4 threads in test_framework.py

Bug:
Change-Id: I36d8849561e7f6986dbdb60f8fc3fef04fba74fa
diff --git a/tools/test_framework.py b/tools/test_framework.py
index e3cfc76..7ef5ff3 100755
--- a/tools/test_framework.py
+++ b/tools/test_framework.py
@@ -87,6 +87,7 @@
 
     if args.tool == 'goyt':
       tool_file = GOYT_EXE
+      tool_args = ['--num-threads=4'] + tool_args
     elif args.tool == 'dx':
       tool_file = DX_JAR
     else: