Switch to our initial stack after switching over to our own trap table.  This removes the need to lock the stack (and cpuinfo) into the TLB on sun4v.
Switch to our initial stack after switching over to our own trap table.  This
removes the need to lock the stack (and cpuinfo) into the TLB on sun4v.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars