[IA64] fix pgtable.h comments

Remove some statements from comments in <asm-ia64/pgtable.h> whose
correctness is page size dependent ... and based on using an 8k
page size, which almost nobody actually uses.
Signed-off-by: Jason Uhlenkott <jasonuhl@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

include/asm-ia64/pgtable.h

@@ -6,7 +6,7 @@
  * the IA-64 page table tree.
  *
  * This hopefully works with any (fixed) IA-64 page-size, as defined
- * in <asm/page.h> (currently 8192).
+ * in <asm/page.h>.
  *
  * Copyright (C) 1998-2004 Hewlett-Packard Co
  *	David Mosberger-Tang <davidm@hpl.hp.com>
@@ -309,15 +309,15 @@ pgd_index (unsigned long address)
 }
 
 /* The offset in the 1-level directory is given by the 3 region bits
-   (61..63) and the seven level-1 bits (33-39).  */
+   (61..63) and the level-1 bits.  */
 static inline pgd_t*
 pgd_offset (struct mm_struct *mm, unsigned long address)
 {
 	return mm->pgd + pgd_index(address);
 }
 
-/* In the kernel's mapped region we have a full 43 bit space available and completely
-   ignore the region number (since we know its in region number 5). */
+/* In the kernel's mapped region we completely ignore the region number
+   (since we know it's in region number 5). */
 #define pgd_offset_k(addr) \
 	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))