[RFC PATCH for 4.18 13/23] x86: Wire up cpu_opv system call

Signed-off-by: Mathieu Desnoyers CC: "Paul E. McKenney" CC: Peter Zijlstra CC: Paul Turner CC: Thomas Gleixner CC: Andrew Hunter CC: Andy Lutomirski

[RFC PATCH for 4.18 13/23] x86: Wire up cpu_opv system call

Signed-off-by: Mathieu Desnoyers CC: "Paul E. McKenney" CC: Peter Zijlstra CC: Paul Turner CC: Thomas Gleixner CC: Andrew Hunter CC: Andy Lutomirski CC: Andi Kleen CC: Dave Watson CC: Chris Lameter CC: Ingo Molnar CC: "H. Peter Anvin" CC: Ben Maurer CC: Steven Rostedt CC: Josh