x86: visws_quirks, fix build error

fix:

 arch/x86/kernel/visws_quirks.c: In function ‘visws_early_detect’:
 arch/x86/kernel/visws_quirks.c:290: error: ‘skip_ioapic_setup’ undeclared (first use in this function)
 arch/x86/kernel/visws_quirks.c:290: error: (Each undeclared identifier is reported only once
 arch/x86/kernel/visws_quirks.c:290: error: for each function it appears in.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/visws_quirks.c b/arch/x86/kernel/visws_quirks.c
index 0c75691..3059eb4 100644
--- a/arch/x86/kernel/visws_quirks.c
+++ b/arch/x86/kernel/visws_quirks.c
@@ -25,6 +25,7 @@
 #include <asm/visws/cobalt.h>
 #include <asm/visws/piix4.h>
 #include <asm/arch_hooks.h>
+#include <asm/io_apic.h>
 #include <asm/fixmap.h>
 #include <asm/reboot.h>
 #include <asm/setup.h>