arm64: Kconfig: Enable HOTPLUG_SMT

Enable HOTPLUG_SMT for SMT control.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250311075143.61078-5-yangyicong@huawei.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>