*.cmake: add license header

this syncs the files with CMakeLists.txt

Change-Id: I94d45ef61d33ee9e43973b5d4e85fab007941f67
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 10f2242..28ae1e2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,11 +1,10 @@
-##
-##  Copyright (c) 2020 Google LLC.
-##
-##  Use of this source code is governed by a BSD-style license
-##  that can be found in the LICENSE file in the root of the source
-##  tree. An additional intellectual property rights grant can be found
-##  in the file PATENTS.  All contributing project authors may
-##  be found in the AUTHORS file in the root of the source tree.
+#  Copyright (c) 2020 Google LLC.
+#
+#  Use of this source code is governed by a BSD-style license
+#  that can be found in the LICENSE file in the root of the source
+#  tree. An additional intellectual property rights grant can be found
+#  in the file PATENTS.  All contributing project authors may
+#  be found in the AUTHORS file in the root of the source tree.
 
 cmake_minimum_required(VERSION 3.5)
 
diff --git a/cmake/cpu.cmake b/cmake/cpu.cmake
index b01e466..255714b 100644
--- a/cmake/cpu.cmake
+++ b/cmake/cpu.cmake
@@ -1,3 +1,11 @@
+#  Copyright (c) 2021 Google LLC.
+#
+#  Use of this source code is governed by a BSD-style license
+#  that can be found in the LICENSE file in the root of the source
+#  tree. An additional intellectual property rights grant can be found
+#  in the file PATENTS.  All contributing project authors may
+#  be found in the AUTHORS file in the root of the source tree.
+
 # Check for SIMD extensions.
 include(CMakePushCheckState)
 
diff --git a/cmake/deps.cmake b/cmake/deps.cmake
index fce8318..e00611f 100644
--- a/cmake/deps.cmake
+++ b/cmake/deps.cmake
@@ -1,3 +1,11 @@
+#  Copyright (c) 2021 Google LLC.
+#
+#  Use of this source code is governed by a BSD-style license
+#  that can be found in the LICENSE file in the root of the source
+#  tree. An additional intellectual property rights grant can be found
+#  in the file PATENTS.  All contributing project authors may
+#  be found in the AUTHORS file in the root of the source tree.
+
 # Generate the config.h to compile with specific intrinsics / libs.
 
 # Check for compiler options.