cpu/arm920t/start.S: include <common.h> to have ROUND() defined

Commit fcd3c87e made include/common.h usable by assembler code but
failed to update cpu/arm920t/start.S

Signed-off-by: Wolfgang Denk <wd@denx.de>

cpu/arm920t/start.S

@@ -24,9 +24,8 @@
  * MA 02111-1307 USA
  */
 
+#include <common.h>
 #include <config.h>
-#include <version.h>
-#include <status_led.h>
 
 /*
  *************************************************************************