apic: move APIC's MMIO region mapping into APIC

apic: move APIC's MMIO region mapping into APIC

When ICC bus/bridge is removed, APIC MMIO will be left
unmapped since it was mapped into system's address space
indirectly by ICC bridge.
Fix it by moving mapping into APIC code, so it would be
possible to remove ICC bus/bridge code later.

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>