x86: move setup_secondary_clock a little bit down in the function

This is done so we call setup_secondary_clock() in the same place x86_64
does. A separate patch for this is appearantly not needed. But clock
initialization is such a delicate thing, that it's safer to do this way

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>