s390/thread_info: Cleanup header includes

asm/thread_info.h requires PAGE_SIZE, which is defined in vdso/page.h,
but doesn't need to include asm/lowcore.h or asm/page.h.

Therefore change the includes accordingly and reduce header dependencies.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Author: hcahca

arch/s390/include/asm/thread_info.h

@@ -9,6 +9,7 @@
 #define _ASM_THREAD_INFO_H
 
 #include <linux/bits.h>
+#include <vdso/page.h>
 
 /*
  * General size of kernel stacks
@@ -24,8 +25,6 @@
 #define STACK_INIT_OFFSET (THREAD_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
 
 #ifndef __ASSEMBLY__
-#include <asm/lowcore.h>
-#include <asm/page.h>
 
 /*
  * low level task data that entry.S needs immediate access to