Using a cross-compiler to fix another issue, the following build error 
occurred for mips defconfig:

arch/mips/fw/arc/misc.c: In function 'ArcHalt':
arch/mips/fw/arc/misc.c:25:2: error: implicit declaration of function 'local_irq_disable'

Fix it up by including irqflags.h.

Signed-off-by: David Rientjes <rientjes@google.com>
---
 arch/mips/fw/arc/misc.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/fw/arc/misc.c b/arch/mips/fw/arc/misc.c
--- a/arch/mips/fw/arc/misc.c
+++ b/arch/mips/fw/arc/misc.c

@@ -11,6 +11,7 @@
  */
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/irqflags.h>
 
 #include <asm/bcache.h>