x86/i8259: Make default_legacy_pic static

The symbol is not used outside of the file, so mark it static.
Signed-off-by: Chen Lifu <chenlifu@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220823021958.3052493-1-chenlifu@huawei.com

arch/x86/kernel/i8259.c

@@ -407,7 +407,7 @@ struct legacy_pic null_legacy_pic = {
 	.make_irq = legacy_pic_uint_noop,
 };
 
-struct legacy_pic default_legacy_pic = {
+static struct legacy_pic default_legacy_pic = {
 	.nr_legacy_irqs = NR_IRQS_LEGACY,
 	.chip  = &i8259A_chip,
 	.mask = mask_8259A_irq,