irq_domain/mips: Allow irq_domain on MIPS

This patch makes IRQ_DOMAIN usable on MIPS.  It uses an ugly workaround
to preserve current behaviour so that MIPS has time to add irq_domain
registration to the irq controller drivers.  The workaround will be
removed in Linux v3.6

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 2354c87..fb698dc 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -11,15 +11,12 @@
 
 #include <linux/linkage.h>
 #include <linux/smp.h>
+#include <linux/irqdomain.h>
 
 #include <asm/mipsmtregs.h>
 
 #include <irq.h>
 
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-}
-
 #ifdef CONFIG_I8259
 static inline int irq_canonicalize(int irq)
 {