mm: make the __PAGETABLE_PxD_FOLDED defines non-empty

Change the currently empty defines for __PAGETABLE_PMD_FOLDED,
__PAGETABLE_PUD_FOLDED and __PAGETABLE_P4D_FOLDED to return 1.
This makes it possible to use __is_defined() to test if the
preprocessor define exists.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

include/asm-generic/4level-fixup.h

@@ -3,7 +3,7 @@
 #define _4LEVEL_FIXUP_H
 
 #define __ARCH_HAS_4LEVEL_HACK
-#define __PAGETABLE_PUD_FOLDED
+#define __PAGETABLE_PUD_FOLDED 1
 
 #define PUD_SHIFT			PGDIR_SHIFT
 #define PUD_SIZE			PGDIR_SIZE

include/asm-generic/5level-fixup.h

@@ -3,7 +3,7 @@
 #define _5LEVEL_FIXUP_H
 
 #define __ARCH_HAS_5LEVEL_HACK
-#define __PAGETABLE_P4D_FOLDED
+#define __PAGETABLE_P4D_FOLDED 1
 
 #define P4D_SHIFT			PGDIR_SHIFT
 #define P4D_SIZE			PGDIR_SIZE

include/asm-generic/pgtable-nop4d-hack.h

@@ -5,7 +5,7 @@
 #ifndef __ASSEMBLY__
 #include <asm-generic/5level-fixup.h>
 
-#define __PAGETABLE_PUD_FOLDED
+#define __PAGETABLE_PUD_FOLDED 1
 
 /*
  * Having the pud type consist of a pgd gets the size right, and allows

include/asm-generic/pgtable-nop4d.h

@@ -4,7 +4,7 @@
 
 #ifndef __ASSEMBLY__
 
-#define __PAGETABLE_P4D_FOLDED
+#define __PAGETABLE_P4D_FOLDED 1
 
 typedef struct { pgd_t pgd; } p4d_t;
 

include/asm-generic/pgtable-nopmd.h

@@ -8,7 +8,7 @@
 
 struct mm_struct;
 
-#define __PAGETABLE_PMD_FOLDED
+#define __PAGETABLE_PMD_FOLDED 1
 
 /*
  * Having the pmd type consist of a pud gets the size right, and allows

include/asm-generic/pgtable-nopud.h

@@ -9,7 +9,7 @@
 #else
 #include <asm-generic/pgtable-nop4d.h>
 
-#define __PAGETABLE_PUD_FOLDED
+#define __PAGETABLE_PUD_FOLDED 1
 
 /*
  * Having the pud type consist of a p4d gets the size right, and allows