x86: move more pagetable-related definitions into pgtable*.h

PAGETABLE_LEVELS and the PTE masks should be in pgtable*.h

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
index bcc8962..1bd5876 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -24,6 +24,8 @@
 #define SHARED_KERNEL_PMD	1
 #endif
 
+#define PAGETABLE_LEVELS	3
+
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */