x86: clean up arch/x86/mm/pageattr.c

do some leftover cleanups in the now unified arch/x86/mm/pageattr.c
file.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h
index 223b003..faa6a96 100644
--- a/include/asm-x86/pgtable_64.h
+++ b/include/asm-x86/pgtable_64.h
@@ -25,6 +25,8 @@
 
 #endif /* !__ASSEMBLY__ */
 
+#define SHARED_KERNEL_PMD	1
+
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */