x86, platform: Change is_untracked_pat_range() to bool; cleanup init

- Change is_untracked_pat_range() to return bool.
- Clean up the initialization of is_untracked_pat_range() -- by default,
  we simply point it at is_ISA_range() directly.
- Move is_untracked_pat_range to the end of struct x86_platform, since
  it is the newest field.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20091119202341.GA4420@sgi.com>

arch/x86/mm/pat.c

@@ -349,11 +349,6 @@ static int free_ram_pages_type(u64 start, u64 end)
 	return 0;
 }
 
-int default_is_untracked_pat_range(u64 start, u64 end)
-{
-	return is_ISA_range(start, end);
-}
-
 /*
  * req_type typically has one of the:
  * - _PAGE_CACHE_WB