x86: Enable forced interrupt threading support

All non threadeable interrupts are marked. Enable forced irq threading
support.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ad74608..e7ef769 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -67,6 +67,7 @@
 	select GENERIC_IRQ_PROBE
 	select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_IRQ_SHOW
+	select IRQ_FORCED_THREADING
 	select USE_GENERIC_SMP_HELPERS if SMP
 
 config INSTRUCTION_DECODER