aom_config.c.template: use current year in Copyright

This matches the behavior of other generated files

Change-Id: Icbd452530830f2113dc9e0caef5ae70c2afe2c22
diff --git a/build/cmake/aom_config.c.template b/build/cmake/aom_config.c.template
index 62f0a10..93a6d8f 100644
--- a/build/cmake/aom_config.c.template
+++ b/build/cmake/aom_config.c.template
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ * Copyright (c) @year@, Alliance for Open Media. All rights reserved
  *
  * This source code is subject to the terms of the BSD 2 Clause License and
  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
diff --git a/build/cmake/aom_configure.cmake b/build/cmake/aom_configure.cmake
index b4f27a8..ebf8a81 100644
--- a/build/cmake/aom_configure.cmake
+++ b/build/cmake/aom_configure.cmake
@@ -445,6 +445,7 @@
   message("--- Git missing, version will be read from CHANGELOG.")
 endif()
 
+string(TIMESTAMP year "%Y")
 configure_file("${AOM_ROOT}/build/cmake/aom_config.c.template"
                "${AOM_CONFIG_DIR}/config/aom_config.c")