MIPS: Allow forced irq threading

All low level interrupts have been marked NO_THREAD, so MIPS can enjoy
the wonderful world of forced threaded interrupt handlers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2639/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -24,6 +24,7 @@ config MIPS
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select HAVE_ARCH_JUMP_LABEL
+	select IRQ_FORCED_THREADING
 
 menu "Machine selection"