Remove ENABLE_TIMESTAMPS to ensure reproducible builds.

Bug: 24349363

The use of __DATE__ makes this build hard to reproduce/diff.

Change-Id: I7d2b05bef53eac7084918f0781107bb920285bdf
(cherry picked from commit 3c19f5eec3bfcd1fcfda72cd02585569b42507a3)
diff --git a/device/include/llvm/Config/config.h b/device/include/llvm/Config/config.h
index ac58972..d63e022 100644
--- a/device/include/llvm/Config/config.h
+++ b/device/include/llvm/Config/config.h
@@ -20,7 +20,7 @@
 #define ENABLE_PIC 1
 
 /* Define if timestamp information (e.g., __DATE___) is allowed */
-#define ENABLE_TIMESTAMPS 1
+/* #undef ENABLE_TIMESTAMPS */
 
 /* Directory where gcc is installed. */
 #define GCC_INSTALL_PREFIX ""
diff --git a/host/include/llvm/Config/config.h b/host/include/llvm/Config/config.h
index cb3d4a3..cb9d87a 100644
--- a/host/include/llvm/Config/config.h
+++ b/host/include/llvm/Config/config.h
@@ -20,7 +20,7 @@
 #define ENABLE_PIC 1
 
 /* Define if timestamp information (e.g., __DATE___) is allowed */
-#define ENABLE_TIMESTAMPS 1
+/* #undef ENABLE_TIMESTAMPS */
 
 /* Directory where gcc is installed. */
 #define GCC_INSTALL_PREFIX ""