x86: unify tss_struct

Although slighly different, the tss_struct is very similar in x86_64 and
i386. The really different part, which matchs the hardware vision of it, is
now called x86_hw_tss, and each of the architectures provides yours.
It's then used as a field in the outter tss_struct.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c
index 05cafcb..3b0ffa3 100644
--- a/arch/x86/kernel/setup64.c
+++ b/arch/x86/kernel/setup64.c
@@ -258,10 +258,10 @@
 				      v, cpu); 
 		}
 		estacks += PAGE_SIZE << order[v];
-		orig_ist->ist[v] = t->ist[v] = (unsigned long)estacks;
+		orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
 	}
 
-	t->io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
+	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
 	/*
 	 * <= is required because the CPU will access up to
 	 * 8 bits beyond the end of the IO permission bitmap.