ACPICA: Add a define for size of struct acpi_srat_generic_affinity device_handle

ACPICA commit be56820b03d8aeabfa6709c4d99bf1711afe7ef1

Replace magic number with a define. Linux kernel code will utilize this
define.

Link: acpica/acpica@be56820b
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: davejiang

include/acpi/actbl3.h

@@ -279,12 +279,14 @@ struct acpi_srat_gic_its_affinity {
  * 6: ACPI_SRAT_TYPE_GENERIC_PORT_AFFINITY
  */
 
+#define ACPI_SRAT_DEVICE_HANDLE_SIZE	16
+
 struct acpi_srat_generic_affinity {
 	struct acpi_subtable_header header;
 	u8 reserved;
 	u8 device_handle_type;
 	u32 proximity_domain;
-	u8 device_handle[16];
+	u8 device_handle[ACPI_SRAT_DEVICE_HANDLE_SIZE];
 	u32 flags;
 	u32 reserved1;
 };