configs: use CONFIG_UNWINDER_ORC only in x86/x86_64
    
    The shipped .config files for i686 have both CONFIG_UNWINDER_ORC and
    CONFIG_UNWINDER_FRAME_POINTER set. This is wrong because those .config
    files should only have CONFIG_UNWINDER_FRAME_POINTER set. As a result
    the build generates
        [...]:warning: override: UNWINDER_ORC changes choice state
    
    4 times.
    
    Move CONFIG_UNWINDER_ORC to x86/x86_64 to correct this. Note that this
    doesn't change the final .config files that the kernel's build system
    actually uses.
    
    Signed-off-by: Paul Bolle <pebolle@tiscali.nl>