Prepares for using a link<> property to connect APIC with CPU and for
changing the CPU APIs to CPUState.

Resolve Coding Style warnings by moving the closing parenthesis of
foreach_apic() macro to next line.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>