mm: include linux/interrupt.h in mm/bounce.c

This fixes a a build failure for 2.6.31-rc4-rt1 (ARCH=arm,
mv78xx0_defconfig and others):

mm/bounce.c: In function 'bounce_copy_vec':
mm/bounce.c:52: error: implicit declaration of function 'local_irq_save_nort'
mm/bounce.c:56: error: implicit declaration of function 'local_irq_restore_nort'
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1249810600-21946-1-git-send-email-u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

mm/bounce.c

@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/hash.h>
 #include <linux/highmem.h>
+#include <linux/interrupt.h>
 #include <asm/tlbflush.h>
 
 #include <trace/events/block.h>