This patch adds the following new interfaces for I/O xAPIC
hotplug. The implementation of these interfaces depends on each
architecture.

    o int acpi_register_ioapic(acpi_handle handle, u64 phys_addr,
			       u32 gsi_base);

        This new interface is to add a new I/O xAPIC specified by
        phys_addr and gsi_base pair. phys_addr is the physical address
        to which the I/O xAPIC is mapped and gsi_base is global system
        interrupt base of the I/O xAPIC. acpi_register_ioapic returns
        0 on success, or negative value on error.

    o int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base);

        This new interface is to remove a I/O xAPIC specified by
        gsi_base. acpi_unregister_ioapic returns 0 on success, or
        negative value on error.
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>