x86, asmlinkage: Make 32bit/64bit __switch_to visible

This function is called from inline assembler, so has to be visible.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1375740170-7446-6-git-send-email-andi@firstfloor.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>