MIPS: Add missing #inclusions of <linux/irq.h>

Add missing #inclusions of <linux/irq.h> to a whole bunch of files that should
really include it.  Note that this can replace #inclusions of <asm/irq.h>.

This is required for the patch to sort out irqflags handling function naming to
compile on MIPS.

The problem is that these files require access to things like setup_irq() -
which isn't available by #including <linux/interrupt.h>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 2a4d50f..2f4d7a9 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -10,6 +10,7 @@
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
 #include <linux/smp.h>
+#include <linux/irq.h>
 
 #include <asm/smtc_ipi.h>
 #include <asm/time.h>