numa: x86_64: use generic percpu var numa_node_id() implementation

numa: x86_64: use generic percpu var numa_node_id() implementation

x86 arch specific changes to use generic numa_node_id() based on generic
percpu variable infrastructure.  Back out x86's custom version of
numa_node_id()

Signed-off-by: Lee Schermerhorn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Eric Whitney <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>