acpi/cpu: add cpu hotplug callback function to match hotplug_handler API

Add cpu hotplug callback function (acpi_cpu_plug_cb) to match hotplug_handler API.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
acpi:ich9: convert cpu hotplug to hotplug_handler API

Convert notifier based hotplug to hotplug_handler API.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
acpi:piix4: convert cpu hotplug to hotplug_handler API

Convert notifier based hotplug to hotplug_handler API,
and remove the unused AcpiCpuHotplug_add().

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
pc: add cpu hotplug handler to PC_MACHINE

Add cpu hotplug handler to PC_MACHINE, which will perform the acpi
cpu hotplug callback via hotplug_handler API.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
pc: Update rtc_cmos in pc_cpu_plug

Update rtc_cmos in pc_cpu_plug() directly, instead of the notifier.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
qom/cpu: remove the unused CPU hot-plug notifier

Remove the unused CPU hot-plug notifier.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
cpu-hotplug: rename function for better readability

Rename:
AcpiCpuHotplug_init --> acpi_cpu_hotplug_init
AcpiCpuHotplug_ops --> acpi_cpu_hotplug_ops
for better readability, just cleanup.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
acpi/cpu-hotplug: introduce helper function to keep bit setting in one place

Introduce helper function acpi_set_cpu_present_bit() to simplify acpi_cpu_plug_cb
and acpi_cpu_hotplug_init, so that we can keep bit setting in one place.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>