x86: fix duplicated TIF on 64-bit

commit 7e991604
and commit eee3af4a

Both use the same TIF number (25) in thread_info_64.h.

This patch changes the TIF ids.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>