Update U-Boot's build timestamp on every compile

Use the GNU 'date' command to auto-generate a new U-Boot
timestamp on every compile.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/lib_i386/board.c b/lib_i386/board.c
index 659f9a2..1734f86 100644
--- a/lib_i386/board.c
+++ b/lib_i386/board.c
@@ -32,6 +32,7 @@
 #include <watchdog.h>
 #include <command.h>
 #include <devices.h>
+#include <timestamp.h>
 #include <version.h>
 #include <malloc.h>
 #include <net.h>
@@ -70,7 +71,7 @@
 
 
 const char version_string[] =
-	U_BOOT_VERSION" (" __DATE__ " - " __TIME__ ")";
+	U_BOOT_VERSION" (" U_BOOT_DATE " - " U_BOOT_TIME ")";
 
 
 /*