KVM: x86: Make kvm_recalculate_apic_map() local to lapic.c

Make kvm_recalculate_apic_map() local to lapic.c now that all external
callers are gone.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20241009181742.1128779-8-seanjc@google.com
Link: https://lore.kernel.org/r/20241101183555.1794700-8-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>