[S390] gettimeofday.S: removed duplicated #includes

Removed duplicated #include's in arch/s390/kernel/vdso32/gettimeofday.S

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vdso32/gettimeofday.S

@@ -9,10 +9,6 @@
  * it under the terms of the GNU General Public License (version 2 only)
  * as published by the Free Software Foundation.
  */
-#include <asm/vdso.h>
-#include <asm/asm-offsets.h>
-#include <asm/unistd.h>
-
 #include <asm/vdso.h>
 #include <asm/asm-offsets.h>
 #include <asm/unistd.h>