ACPI / scan: constify ACPI device ids

Make the button ACPI device ID array static const. Safes us a little bit
of code.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/scan.c

@@ -1673,7 +1673,7 @@ static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
 
 static void acpi_wakeup_gpe_init(struct acpi_device *device)
 {
-	struct acpi_device_id button_device_ids[] = {
+	static const struct acpi_device_id button_device_ids[] = {
 		{"PNP0C0C", 0},
 		{"PNP0C0D", 0},
 		{"PNP0C0E", 0},