ACPI / processor: Make it possible to get local x2apic id via _MAT

Logical processors with APIC ID values of 255 and greater are
required to have a Processor Device object and must convey the
processor's APIC information to OSPM using the Processor Local
X2APIC structure, but not until ACPI 5.1, X2APIC structure was
not supported in _MAT method.

_MAT is needed for CPU hotplug and system with more than 255
CPUs will definitely need X2APIC structure, so add its support
in map_mat_entry() to make it possible to get local x2apic id
via _MAT based on ACPI 5.1.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/processor_core.c

@@ -135,6 +135,8 @@ static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
 		map_lapic_id(header, acpi_id, &apic_id);
 	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
 		map_lsapic_id(header, type, acpi_id, &apic_id);
+	} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
+		map_x2apic_id(header, type, acpi_id, &apic_id);
 	}
 
 exit: