[test] Make generated tests satisfy VIXL's clang-format

The test generator would use Google's style guide instead of VIXL's when
running clang-format over the generated files. Now that VIXL has its own
".clang-format", let's use it.

Change-Id: I960ed290d1b7e762da9e96f105b83e749ed560a5
diff --git a/tools/generate_tests.py b/tools/generate_tests.py
index 23576fc..06e89f4 100755
--- a/tools/generate_tests.py
+++ b/tools/generate_tests.py
@@ -751,8 +751,8 @@
   with open(
       "test/aarch32/test-{}-{}.cc".format(generator.test_type, generator.test_name),
       "w") as f:
-    proc = subprocess.Popen([clang_format, "-style=google"],
-                            stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+    proc = subprocess.Popen([clang_format], stdin=subprocess.PIPE,
+                            stdout=subprocess.PIPE)
     out, _ = proc.communicate(generated_file.encode())
     f.write(out.decode())
   # Write dummy trace files into 'test/aarch32/traces/'.